REVIEW ARTICLE

Avoiding Complications in Patellofemoral Surgery

Ryan K. Harrison, MD, Robert A. Magnussen, MD, and David C. Flanigan, MD

In addition, it is important to understand any trauma or

Abstract: The diagnosis and treatment of patellofemoral disorders inciting event that was associated with the onset of symp-
can challenge even the experienced orthopedic surgeon. Differential toms. Aggravating and alleviating factors should be dis-
diagnosis is broad and multiple anatomic abnormalities must be cussed with the patient as well as any previously attempted
taken into account in order to manage care. The majority of
patients with patellofemoral disorders can be treated successfully
treatment and the success or failure thereof.
nonoperatively. When nonoperative management fails, and in the A complete physical examination of the knee joint
carefully selected patient, a variety of surgical options exist based should be performed and compared with the contralateral
on the anatomic pathology involved, but each brings its own side. Overall lower extremity alignment and any generalized
potential for complication. We discuss several of the surgical ligamentous laxity (hyperextension of the knees or elbows
treatment options that are available to the orthopedic surgeon for or in the hand) should be noted. It is important to docu-
the treatment of patellofemoral disorders, including lateral reti- ment the range of motion and any signs of ligamentous
nacular release, medial soft-tissue reconstructive procedures, and instability. The patella should be examined for crepitus
bony procedures (including trochleoplasty and tibial tubercle during range of motion, which may indicate arthrosis. In
osteotomy. We describe potential complications of each procedure
addition, the patella should be examined for signs of
and what the orthopedic surgeon can do to avoid them.
instability, including apprehension, excessive subluxation,
Key Words: patellofemoral, complications, trochleoplasty, tibial or frank dislocation. Other key aspects of patellofemoral
tubercule osteotomy, lateral retinacular release, cartilage examination include evaluation of the feet (pes planus,
hindfoot issues), tibial torsion (thigh foot angle), and fem-
(Sports Med Arthrosc Rev 2013;21:121–128) oral version (excessive internal rotation), and strength and
stability of the core.
After an appropriate history and physical examination,

S uccessful management of patellofemoral disorders can

be challenging for even the most experienced orthopedic
surgeons. The differential diagnosis is broad and there are
imaging should be ordered as necessary. Plain radiographs
including anteroposterior, lateral, and patellar views should be
reviewed before any advanced imaging is ordered. If necessary,
often multiple anatomic abnormalities that must be con- computed tomography scan and/or magnetic resonance
sidered to adequately address the patient’s problem. Just as imaging can allow for further examination of the bony and
there are a variety of causes of patellofemoral dysfunction, soft-tissue/cartilage anatomy, respectively.
there are a variety of surgical procedures that can be uti-
lized in their treatment once conservative measures have
been exhausted. Each of these procedures is fraught with INITIAL MANAGEMENT
potential complications. Conservative measures should be exhausted in patients
In this review, we will outline several of the surgical with atraumatic patellofemoral dysfunction before oper-
treatment options that are available to the orthopedic sur- ative procedures are considered. First and foremost, it is
geon for the treatment of patellofemoral disorders. The imperative that the correct diagnosis is made and that
treatment options that will be discussed include lateral all causes of pain and dysfunction have been properly diag-
retinacular release (LRR), medial soft-tissue reconstructive nosed. Once this aim is achieved, a careful and compre-
procedures, bony procedures [including trochleoplasty and hensive physical therapy program can be initiated.
tibial tubercle osteotomy (TTO)], and cartilage procedures. Paramount in this program are stretching and strengthening
We will outline the potential complications of each proce- of the quadriceps mechanism, especially the vastus medialis
dure and how orthopedic surgeons can try to avoid these obliquus. Other stabilizing structures about the knee, such as
potential pitfalls. the hamstrings and hip abductors should be appropriately
stretched and or strengthened to ensure a full range of motion
INITIAL EVALUATION about the knee. Furthermore, focus on the core stabilizers
Patients, who present with patellofemoral symptoms is just as important, including abdominal, back, and hip
are a heterogeneous population. The differential diagnosis musculature strengthening and proprioception.
is broad, and performance of a thorough history and In addition to strengthening and stretching, other
physical is critical. The exact nature of a patient’s pain and modalities such as iontophoresis, ultrasound, and heat may
any symptoms of instability should be carefully explored. be utilized. Nonsteroidal anti-inflammatory medications
can help to ease pain. Taping, bracing, and orthotics may
From the Department of Orthopaedics, The Ohio State University
help to provide support and stability as strengthening
Sports Medicine Sports Health & Performance Institute, Columbus, progresses. No matter what strategies are utilized, it is
OH. important to complete a full 4- to 6-month course of non-
Disclosure: D.C.F. serves as consultant for Sanofi and Smith & operative management. If this treatment fails, then and
Nephew. The remaining authors declare no conflict of interest.
Reprints: David C. Flanigan, MD, OSU Sports Medicine Center, 2050
only then should an operative course be considered. Proper
Kenny Road, Suite 3100, Columbus, OH 43221. patient selection is very important in the success of oper-
Copyright r 2013 by Lippincott Williams & Wilkins ative treatment of patellofemoral disorders.

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Harrison et al Sports Med Arthrosc Rev  Volume 21, Number 2, June 2013

LRR performing combined procedures, it is important to

Once thought to be an effective isolated procedure for understand that overzealous tightening of the medial
patellofemoral disorders from anterior knee pain to recur- structures in the setting of incompetent lateral structures
rent dislocation, recent literature has discouraged liberal may lead to medial subluxation and/or dislocation.
use of the LRR. Long-term follow-up studies have revealed Iatrogenic medial patellar subluxation can be treated
that, although isolated LRR may provide good to excellent with lateral retinacular closure.8 This is an open technique
short-term results in the treatment of these disorders, these in which the retinacular defect is identified and sutured
effects fade overtime.1 Specifically, the use of isolated LRR closed with No. 0 Vicryl in a figure-of-eight manner. It is
for treatment of patellofemoral arthrosis has been shown to important in this technique to examine the knee after the
be ineffective. In the setting of lateral patellar instability, procedure has been completed to ensure adequate tracking
reports have shown that instead of balancing the patello- and alignment of the patella. Patients are allowed to bear
femoral articulation, the LRR increases lateral instability.2 weight immediately postoperatively and are taken through
Once the lateral retinaculum has been released, the normal a 12-week supervised rehabilitation program, after which
pull of the retinaculum on the patella down into the they are allowed to return to activities. This procedure has
trochlear groove is no longer available, leading to an been shown to provide good to excellent results in 82% of
increased risk of instability.2 Literature has shown that the patients who were examined. All but 1 patient increased
LRR can be useful in isolated circumstances, such as with his activity level postoperatively. The patient who did not
excessive patellar tilt or in combination with other correc- increase her activity level cited unrelated health reasons for
tive procedures to provide appropriate patellar tracking. not doing so. This procedure can also be carried out
In addition to poor outcomes, it has been well docu- arthroscopically and then tied through a small lateral
mented in the literature that if not performed carefully, incision (Figs. 1, 2).
LRR can lead to significant morbidity and dysfunction One additional technique for the correction of iatro-
(Table 1). DiGiulio and colleagues described an overall genic medial patellar instability is iliotibial band transfer to
complication rate of 7.2%, which is higher than the overall reconstruct the lateral patellatibial ligament. In this pro-
complication rate with knee arthroscopy.3–4 Specific com- cedure, a 1  4 cm strip of the iliotibial band is used to
plications seen with LRR include hemarthrosis, infection, augment the insufficient ligament. The repair is tensioned in
reflex sympathetic dystrophy, recurrent patellar dislocation, the position of greatest instability. A supervised rehabil-
overrelease leading to iatrogenic medial subluxation, skin itation program is prescribed. This technique has been
burns, and quad rupture. shown to prevent recurrent medial instability.9
LRR can lead to recurrent dislocation and pain. One Hemarthrosis can be a significant source of pain and
study revealed a 35% redislocation rate in patients who discomfort for patients after LRR. Incidence in the liter-
underwent isolated LRR for the treatment of patellar ature has been reported to be between 1% and 42%.1 To
instability, often because of an incomplete release.1 If one is avoid this complication, it is important to ensure good
going to use LRR in combination with other procedures, it hemostasis and to know that the lateral geniculate artery is
is important to ensure that the lateral structures are nearly always cut during this procedure. This can lead to
appropriately balanced which may be a partial release or significant hemarthrosis and pain and even require repeat
lateral lengthening procedure. When done arthroscopically, operation if the artery is not properly ligated or cauterized.
this means the lateral retinaculum, vastus lateralis obliquus Other suggestions to avoid hemarthrosis include avoiding
(if present), and distal patellotibial band should be released.
This requires releasing all tissues 5 mm lateral to the lateral
border of the patella from 1 cm superior to the patella to the
anterolateral portal.5 When performing this procedure, it is
important to note that these structures may need to be
released in a step-wise manner, checking throughout to find
the point of balanced lateral and medial structures and a
well-aligned extensor mechanism.
Too excessive a release (removing the vastus lateralis
insertion from the patella) can lead to medial subluxation
or dislocation. In 1 study by Hughston et al,6 65 patients
undergoing repeat surgery for medial subluxation of their
knee, 58 had undergone LRR. Hughston and Deese7
examined 60 knees undergoing repeat surgery for failed
LRR in another study. Thirty of these patients were
found to have medial instability on examination. When

TABLE 1. Common Complications Associated With Lateral

Retinacular Release
Hemarthrosis
Infection
Reflex sympathetic dystrophy
Recurrent patellar dislocation
Overrelease leading to iatrogenic medial subluxation FIGURE 1. Arthroscopic image of a 22-year-old woman with a
Skin burns history of recurrent instability, both medial and lateral, despite
Quadriceps rupture prior lateral release. This image reveals incompetent lateral
structures.

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Sports Med Arthrosc Rev  Volume 21, Number 2, June 2013 Avoiding Complications in Patellofemoral Surgery

TABLE 2. Common Complications Associated With Medial

Patellofemoral Ligament Reconstruction
Patellar fracture
Postoperative instability
Flexion loss
Residual pain

fade, resulting in poorer outcomes and recurrent episodes

of instability/dislocation/pain.3

MPFL RECONSTRUCTION
In the setting of acute patellar dislocation, the medial
supporting structures are often torn. In chronic patellar
instability, the MPFL may become incompetent, allowing
for lateral subluxation and/or dislocation. There are
numerous described techniques for reconstruction of the
MPFL, including using a variety of graft materials and
fixation in both the distal femur and medial patella. A
recent systematic review of complications related to MPFL
reconstruction was published.14 The complication rate was
FIGURE 2. This arthroscopic image demonstrates the lateral 26.1% (164 complications in 629 knees). This paper out-
retinacular structures after placement for repair. Sutures were lines 4 major complications following this procedure:
passed under arthroscopic visualization and then secured using a patellar fracture, postoperative instability, flexion loss, and
small lateral skin incision. pain (Table 2).
Twelve patients required return trips to the operating
tourniquet use, using drains, and using an arthroscopic room for fixation of patella fracture. Three types of patella
technique (which uses electrocautery) as opposed to open fractures have been reported after MPFL reconstruction.
techniques (which often utilize a sharp division of the Parikh and Wall15 proposed a classification for these frac-
retinaculum). tures. Type I fractures are those that occur thru 1 or 2 drill
Quadriceps rupture has also been described after LRR holes in the patella created for the passage of graft materials
and is attributed to overaggressive release.3–4 When this thru the patella to fix the repair distally. Although this
occurs, it is important to repair the quadriceps mechanism construct is biomechanically strong in the sense of fixation
as expeditiously as possible and start the patient on an for the graft material, it also creates a stress riser in the
aggressive physical therapy regimen as soon as safe to patella, which can lead to fracture. Tanaka et al16 suggested
prevent loss of motion and excessive arthrofibrosis. that the causation behind this fracture is a breach of the
Skin burns are one final potential complication of anterior cortex (Fig. 3) during placement of the drill holes.
LRR. This occurs with aggressive use of electrocautery that Shah et al14 noted in their systematic review that no frac-
results in an inside-out burn of the subcutaneous tissues tures were observed in patients who underwent distal fix-
and skin. This can be avoided by being certain not to cut ation through a docking technique, anchors or soft-tissue
thru fatty tissue during the release. These burns are rela- attachment to the patella. Type II fractures are proximal
tively rare (1 study listed 3 such burns out of 85 LRR avulsion fractures. These fractures are thought to be caused
procedures) if the treating surgeon is cautious, but if not by one of 3 procedures: proximal realignment, lateral
recognized, can lead to complications such as skin break- release, and/or excessive dissection of the superior aspect of
down, septic arthritis, and need for scar revision.10 the patella. The prevailing theory as to the cause of these
fractures is disruption of the blood supply to the proximal
patella. Therefore, it is recommended that at least 1 geni-
culate artery be spared when performing these procedures.
MEDIAL SOFT-TISSUE RECONSTRUCTION Type III fractures are fractures that occur on the medial
In recent years, the medial patellofemoral ligament aspect of the patella postoperatively after a traumatic event,
(MPFL) reconstruction has become the mainstay of treat- often resulting in repeated patellar dislocation. This often
ment for recurrent patellar instability. This procedure, if requires open reduction and internal fixation to repair the
performed correctly, has been reported to have excellent fractured piece and thus once again reconstitute the MPFL
outcomes and prevent recurrent instability episodes.11 complex.
Early medial soft-tissue procedures included vastus Postoperative instability can be the result of failure of
medialis reefing, vastus medialis advancement, and medial fixation leading to a feeling of apprehension or worse,
tethering of the patella or patella tendon. These procedures repeat instability events. Loss of fixation occurs most often
were often performed in concert with LRR and both open on the patellar side. Shah et al14 showed in their systematic
and arthroscopic procedures have been described. Similar review that 52 of 629 patients had symptoms of residual
to LRR, these procedures have been described to have instability. Only 6 patients, however, were returned to the
excellent short-term outcomes. Recurrence rates have been operating room for revision of their MPFL reconstruction.
reported as 10% for open techniques and 0% to 3.6% for Although the review by Shah and colleagues could not pool
arthroscopic techniques.12–13 Long-term data, however, enough data to reach a statistical significance, they did
have revealed that as soft tissues loosen, the results begin to notice a trend towards increased failure in patients who

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Harrison et al Sports Med Arthrosc Rev  Volume 21, Number 2, June 2013

overload, iatrogenic medial subluxation, recurrent lateral

instability, flexion loss, and residual anterior knee pain.17
Loss of knee range of motion is the third complication
reported by Shah and colleagues. They noted that 13.4% of
the patients in their study required a return trip to the
operating room for manipulation under anesthesia.14 This
complication is thought to be caused by improper ten-
sioning on the MPFL, improper positioning of the graft, or
a delay in the initiation of physical therapy to work on
motion with no restrictions (as long as no bone procedure
was done at the time of surgery).14
The MPFL is a nonisometric ligament, being tight
only in the first 20 degrees of flexion, before the patella
enters the trochlea. This is the time when the MPFL acts as
a restraint to lateral subluxation/dislocation. Beyond that
first 20 degrees, the bony structures are important for
maintaining the patella within the trochlear groove.
Improper tensioning on the ligament can lead to loss of
range of motion in the knee and up to a 50% increase in the
peak pressures experienced in the patellofemoral joint.17 To
properly tension the MPFL graft, proper femoral fixation is
thought to be critical, as described above. The appropriate
location for fixation on the patella is at the anatomic
insertion of the MPFL, at the proximal half of the medial
border of the patella.16
In addition to an appropriate starting point, fixating
the graft at the appropriate angle of knee flexion is also
important.14 It is thought that patients whose grafts are
fixed at Z60 degrees of flexion experience fewer episodes of
instability or loss of range of motion, but there is very little
evidence in the literature currently to suggest the appro-
priate angle of knee flexion. Bollier et al17 suggest holding
the lateral border of the patella flush with the trochlea at 30
degrees of knee flexion while the graft is tensioned to pre-
vent overtightening. Although the exact degree in which to
FIGURE 3. Lateral radiograph of the knee after medial patello- tension the graft is debated, it is likely important to have
femoral ligament reconstruction in a 15-year-old female athlete the graft at resting tension with the knee bent at least
for recurrent patellar dislocation. Note the breach of the anterior 30 degrees with the patella centered in the trochlea groove
cortex of the patella, placing the patient at risk for iatrogenic to create a checkrein to lateral translation without over-
fracture. tensioning the patella. If this is carried out correctly, one
should see the patella engage within the center of trochlear
underwent fixation methods in the patella other than tun- grove at 20 to 30 degrees of knee flexion.
nels. They also proposed that repeat episodes of instability Pain is also a significant complication following MPFL
could potentially be because of failure to recognize and reconstruction, as up to 26% of patients require return trips to
address other anatomic abnormalities.14 the operating room for subsequent procedures related to their
Bollier et al17 described 5 cases in which patients MPFL reconstruction.14 One common need for return to the
underwent revision reconstruction for recurrent instability operating room is for removal of hardware. The patella and
episodes (3 with medial subluxation and 2 with lateral distal femur can be relatively subcutaneous in patients and
subluxation). They noted that in 4 of these patients, the prominent hardware is not well tolerated. It is important to
femoral tunnel was too proximal, whereas all 5 patients had recognize this and attempt to avoid it or explain to patients
femoral tunnels that were too anterior. On the lateral ahead of time that a return trip to the operating room may be
radiograph of the knee, Schottle et al18 described the point indicated for hardware removal. Shah and colleagues noted
1 mm anterior to the posterior cortex and 2.5 mm distal to that 34 of 629 patients had substantial and ongoing pain
the posterior origin of the femoral condyle, proximal to postoperatively. Nineteen patients reported prominent hard-
Blumensaat line as the appropriate location for the femoral ware as the source of the pain, with 7 returning to the oper-
tunnel in MPFL reconstruction. The following suggestions ating room for removal of hardware. Fifteen patients reported
are made for confirming appropriate femoral placement of ongoing pain, but no hardware prominence could be found as
the graft: using an appropriate-sized skin incision and the cause of their pain.
palpation of the MPFL origin, using the adductor magnus
tendon as a landmark (the MPFL origin being anterior and
distal the adductor magnus tendon), using fluoroscopy to BONY PROCEDURES
confirm appropriate tunnel placement, and using free Although soft-tissue procedures are often necessary in
suture to confirm graft isometry). Failure to properly the treatment of patellofemoral disorders, bony procedures
position the femoral tunnel can lead to several potential may be necessary as well, especially in the setting of
adverse outcomes: medial patellofemoral articular trochlear dysplasia, resulting in decreased bony restraint to

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Sports Med Arthrosc Rev  Volume 21, Number 2, June 2013 Avoiding Complications in Patellofemoral Surgery

lateral patellar subluxation at higher levels of flexion. In

addition, bony procedures can be utilized to assist in TABLE 3. Common Complications Associated With
Trochleoplasty
realignment in the setting of patellar alta or excessive lat-
eralization of the tibial tubercle. Finally, patellar tendon Thermal injury leading to cartilage death
realignment can be used to offload areas of increased con- Residual instability
tact in the arthritic patellofemoral joint or to protect car- Residual pain
Arthritis
tilage restoration procedures postoperatively.

secondary to damage to underlying subchondral bone and

TROCHLEOPLASTY chondral damage, which may be the result of troch-
The trochlear groove is important for maintaining leoplasty, but could also be the sequelle of recurrent epi-
patellar stability beyond 30 degrees of flexion. Trochlear sodes of instability before treatment.21–25 This arthrosis
dysplasia can be identified on plain radiographs most reli- could also be caused by the high-grade dysplasia often
ably on the lateral projection, noting the crossing sign or a noted in these patients.
double trochlea.19 A supra trochlear spur may also be The Albee opening-wedge osteotomy is a procedure in
present. On axial imaging, the trochlea may be shallow or which the lateral trochlear facet is elevated. This procedure,
flat to convex. Indications for trochleoplasty include high- although effective at managing instability, is not commonly
grade trochlear dysplasia with instability or abnormal used because it can cause overloading of the joint and early-
patellar tracking in the absence of osteoarthritis. Open onset arthritis.26 Beriter trochleoplasty is another described
growth plates and patellofemoral arthrosis are contra- technique that, although successful in the treatment of
indications.20 Dejour and Saggin classified trochlear dys- instability, leads to increased incidence of arthritis.24
plasia into 4 types. Treatment is dependent upon the type,
as types B and D should be treated with trochleoplasty.
Type A should be treated nonoperatively and type C can be
treated with lateral facet elevating trochleoplasty, although TTO
this is controversial.19 Complications commonly associated
TTOs are common procedures for treating patients
with trochleoplasty include thermal injury leading to car-
with both pain and instability. This procedure is often
tilage death, recurrent instability and pain, and post-
performed when patients have malalignment issues with
operative arthritis (Table 3).
either abnormal patellar height or abnormal tibial tubercle-
The sulcus deepening trochleoplasty or Lyon proce-
trochlear groove distance (indicating lateralization of the
dure is a reliable method to correct trochlear dysplasia. The
force vector across the patellofemoral joint).27–29 This
subchondral bone beneath the femoral condyles is removed.
procedure can allow for correction of both patellar height
This allows the cartilaginous surface to be molded to create
(in the case of alta or baja) and correction of the tibial
a new trochlear groove. The cartilage is then affixed to the
tubercle-trochlear groove distance, and can be used to ele-
bone using staples. This technique has been shown to reli-
vate the tubercle to reduce forces on the patella and
ably recreate the bony restraint to patellar dislocation at
trochlea. There are several procedures that have been
higher levels of flexion.17
described in the literature. The Fulkerson osteotomy is an
It is important when performing the Lyon procedure
anteromedialization of the tibial tubercle and is a mod-
to avoid under or over correction of the trochlea, as this can
ification of the procedures originally described by Elmsilie,
lead to either recurrent dislocation or increased pressures
Trillat, and Maquet.30 The Maquet procedure is anteriori-
on the patellofemoral joint and early arthrosis. In addition,
zation of the tubercle alone with iliac crest autograft for the
one must be cautious to leave an appropriate shell of bone
purpose of unloading the patellofemoral joint. The Bandi
beneath the cartilage. Too little bone can lead to thermal
osteotomy is an anteriormedialization procedure with the
injury and cartilage death.
addition of autogenous bone graft harvested from the
Dejour and Saggin described 2 groups of patients who
proximal tibial metaphysis.29,31
underwent trochleoplasty. The first group was of 18
Although several different osteotomy techniques that
patients who had revision of prior surgery for severe pain or
have been described, there are certain potential complications
residual instability. The second group consisted of 44
that are common in all cases (Tables 4 and 5). These include
patients who underwent trochleoplasty as a portion of their
fracture, nonunion/malunion, vascular injury, compartment
index procedure for recurrent instability. In the first group,
syndrome, hardware prominence, pain, wound complications,
65% of the patients were satisfied or very satisfied, how-
and deep vein thrombosis. The complication rate after TTO
ever, 18% of patients developed residual pain and
has been reported to be up to 37%.32
2 patients developed patellofemoral arthritis.19 Of the
patients in the second group, only 5% of patients developed
residual pain and no patients developed arthritis. This TABLE 4. Common Complications Associated With Tibial
would suggest that trochleoplasty is most effective when it Tubercle Osteotomy
is done in conjunction with other stabilizing procedures at Fracture
the time of index surgery. Malunion/nonunion
There are a number of other studies in the literature Vascular injury
that describe outcomes of trochleoplasty. Each of these Compartment syndrome
studies report that patients who undergo trochleoplasty Hardware prominence
have excellent results in that recurrent instability is very Pain
Arthrofibrosis
rare. Formation of arthritis and residual pain, however, is
Wound complications
quite common, occurring in 25% to 50% of each of the Deep vein thrombosis
study populations. This complication is thought to be

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Harrison et al Sports Med Arthrosc Rev  Volume 21, Number 2, June 2013

(Fig. 4). Avoiding use of a saw to finish the osteotomy can

TABLE 5. Common Complications Associated With Cartilage avoid thermal necrosis. Instead, an object such as an
Procedures
osteotome can be used to finish the osteotomy. For medi-
Increased incidence of complications related to concomitant alization procedures, one may choose to not finish the distal
procedures cut at all, but to instead cause more of a “greenstick”
Graft hypertrophy leading to mechanical symptoms fracture at the site by performing the transfer without
Arthrofibrosis
completing the osteotomy at the distal aspect. Other studies
Pain
have discussed not stripping the periosteum from the distal
aspect of the osteotomy in an attempt to preserve the blood
supply and, in turn, promote healing.3,38 When using the
Secondary fracture of the tibia after correction of Maquet and Bandi osteotomies, it is necessary to bone graft
patellofemoral malalignment has been reported to occur. the osteotomy site, using either cancellous allograft or
There are multiple reports in the literature of patients sus- autograft harvested from the iliac crest.29,31 Bone grafting
taining fractures after TTO to correct malalignment.14,33–35 with autologous bone graft, however, is not without its own
In the Maquet procedure, commonly described fractures potential donor site morbidity.
are of the tibial tubercle itself. Conversely, in the Fulkerson Hardware irritation is another problem common to all
osteotomy, fractures are often in the metaphyseal region, types of osteotomies and has been reported to be a com-
just below the level of the osteotomy. The prevalence rate of plication in up to 96% of osteotomies.3 After creation of
fracture has been described anywhere from 0% to 9.5%, the osteotomy and appropriate realignment, either 1 or 2
with most descriptions in the literature being single case cortical or cancellous screws are used to fix the bone in
reports or small case series.35 place, depending on the type of osteotomy used. Given the
To avoid potential risk of fracture intraoperatively, subcutaneous nature of the tibial tubercle, it is important to
cautious use of power saws and osteotomes to prevent ensure that the screws are countersunk to avoid hardware
extension of the osteotomy distally or posteriorly weaken- irritation. Despite the best efforts by many, hardware
ing the bone is essential. This is most important if the removal is commonly required to provide pain relief.
tubercle is to be shifted with a distal hinge. Taking too thick Vascular injury, although rare is a real possibility if
a piece of bone for the osteotomy should be avoided, as this one is not aware of the proximity of the vascular structures
can lead to development of a stress fracture at the level of to the posterior aspect of the tibia. Kline and colleagues
or distal to the osteotomy site. It is important to protect a showed that the bifurcation of the popliteal artery is a mean
patient’s weight bearing in the postoperative period. The of 8.3 mm from the common exit point of the superior drill
most recent recommendation is to allow patients to work bit. The tibial artery was a mean distance of 9 mm from the
on passive range of motion immediately postoperatively, exit point of the inferior drill bit. Screws that are too long
but to prescribe protected weight bearing for 6 to 8 weeks and can cause vascular injury and consequently have dev-
after surgery. In addition, patients should be counseled to astating consequences. Kline et al39 recommended in his
avoid high-impact activities for up to 6 months and com- study that extreme care be taken to not drill past the pos-
petitive sports for 9 months to a year.33–36 terior cortex to avoid this complication.
Nonunion and malunion are problems associated with Wound complications are common with the elevation
all types of TTO, although the incidence is relatively rare procedures of the tibial tubercle such as the Maquet but less
and most accounts are single case presentation.37 These common with the Fulkerson technique.3,32 Up to a 50%
issues are commonly because of operative technique complication rate has been reported with the Maquet

FIGURE 4. Axial (A) and saggital (B) computed tomography images. The patient is a 28-year-old woman, who underwent tibial tubercle
osteotomy in conjunction with autologous chondrocyte implantation for recurrent patellar instability and anterior knee pain recalcitrant
to conservative measures. These images were obtained at the patient’s 3-month postoperative visit and demonstrate nonunion of her
transfer, despite bone stimulator use. The patient describes continued pain and will require a repeat operation to achieve bony healing.

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Sports Med Arthrosc Rev  Volume 21, Number 2, June 2013 Avoiding Complications in Patellofemoral Surgery

technique. This can lead to wound breakdown and the need 2. Christoforakis J, Bull AM, Strachan RK, et al. Effects of
for rotation flap or free flap for coverage. Osteomyelitis was lateral retinacular release on the lateral stability of the patella.
shown to develop in 5.8% of 1 series secondary to exposed Knee Surg Sports Traumatol Arthrosc. 2006;14:273–277.
bone and hardware.32 Many authors advocate using full- 3. Digiulio M, Donadson WR. Complications of patello-femoral
joint surgery. Sports Med Arthrosc Rev. 2004;12:172–184.
thickness skin flaps and judicious elevation of the tubercle 4. Blasier RB, Ciullo JV. Rupture of the quadriceps tendon after
to prevent skin issues. arthroscopic lateral release. Arthroscopy. 1986;2:262–263.
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