Editorial Commentary: The Medial Patellofemoral Complex Is Composed of the Medial Patellofemoral Ligament and the Medial Quadriceps Tendon–Femoral Ligament: Do We Need to Reconstruct Both?

The medial patellofemoral ligament (MPFL) has been known as the primary soft-tissue restraint to lateral patellar translation. More recent anatomic studies have identified additional fibers that extend to the quadriceps tendon (medial quadriceps tendon–femoral ligament [MQTFL]), leading to the use of the term “medial patellofemoral complex” (MPFC) to describe the broad and variable attachment of this complex on the patella and quadriceps tendon. Whereas many techniques and outcomes of traditional MPFL reconstruction have been described, fewer reports exist on anatomic MPFC reconstruction to recreate both bundles of this complex. To date, the specific biomechanical roles of, and indications for, reconstruction of the MPFL versus MQTFL fibers have not been defined. One primary benefit of MQTFL reconstruction has been to avoid the risk of patella fracture, which is not obviated in the setting of concurrent patellar fixation when reconstructing both components of the MPFC. The risks and benefits comparing fixation on the patella, quadriceps tendon, or both with anatomic double-bundle reconstruction remain to be determined. Additional studies are needed to understand the differences between reconstructing the proximal and distal fibers of the MPFC with regard to graft length changes and femoral attachment sites, in order to optimally recreate the function of each graft bundle in the surgical treatment of patellar instability.     

Editorial Commentary: From Lateral Release and Medial Plication to Complex Medial Patellofemoral Ligament Reconstruction Techniques: Medial Quadriceps Tendon Femoral Ligament Reconstruction Is the Most Anatomic Repair

Patella instability and dislocation are common in younger patients, and 1 in 5 patients are at risk of recurrent dislocations. Conservative treatment should be considered for first dislocations unless other concomitant injuries are present. Historically, lateral patella release and medial plication techniques were used for repair but have been superseded by medial patellofemoral ligament reconstruction. Overconstraint is a potential problem and often related to nonanatomic femoral tunnel position and graft tension, which could result in increased patellar contact pressures and graft failure. The medial quadriceps tendon–femoral ligament reconstruction technique (MQTFL) avoids patellar tunnels without the risk of patella fracture. When comparing medial patellofemoral ligament, MQTFL, and the combination of both techniques in a cadaver model, MQTFL resulted in less constraint with no differences for patellar contact pressures. Medial quadriceps tendon femoral ligament reconstruction is the most anatomic repair.     

Reconstruction of the Medial Patellofemoral Ligament With Autologous Quadriceps Tendon

In knees with insufficient or previously disrupted medial retinacular and patellofemoral ligaments caused by subluxation or dislocation, anatomic reconstruction of the medial patellofemoral ligament may be performed. This procedure involves harvesting of an 8 × 70-mm medial quadriceps tendon graft, which leaves the quadriceps tendon retinacular attachment intact and avoids patellar and femoral drill holes. This graft is passed beneath the retinaculum adjacent to the femoral epicondyle and is sutured to the medial intermuscular septum—a procedure that reproduces the medial patellofemoral ligament and is supported by imbrication of the remaining medial retinaculum. The tension of the graft and of the medial retinaculum is set at closure with the knee in 30° to 45° of flexion; this allows the patella to be moved a distance equal to 25% of its width. Avoidance of drill holes allows the procedure to be used regardless of skeletal maturity and reduces fracture complications, inadequate graft placement, and failure of fixation. Postoperative rehabilitation includes immediate knee motion from 0° to 90° and partial weight bearing.     

Editorial Commentary: The Best Medial Patellofemoral Reconstruction May Include Components of Both Quadriceps and Patellar Attachments

Given different functions of the medial quadriceps tendon–femoral ligament and medial patellofemoral ligament components of the proximal medial patellar restraints, reconstructions to the midpoint of the medial patellofemoral ligament and medial quadriceps tendon–femoral ligament are probably optimal, combining the benefits of both in surgical treatment of recurrent patella instability.     

Editorial Commentary: The “F” in MPFL (Medial Patellofemoral Ligament) Reconstruction—How Should We Fix It and Does It Matter?

Our understanding of the medial patellofemoral complex anatomy has evolved significantly over the past several decades, and this has informed our current surgical approach to management of lateral patellar instability. Medial patellofemoral ligament reconstruction remains the gold standard for decreasing the risk of secondary patellar dislocation and returning patients to active physical function. However, concerns about isometry, overconstraint, secondary arthrosis, and surgical-site morbidity remain with femoral socket fixation, particularly when patella alta, rotational malalignment, or hypermobility is present. Medial patellofemoral ligament reconstruction with soft-tissue fixation, on either the patellar or femoral side, may mitigate some of these risks by offering a more dynamic checkrein to lateral translation. However, longer-term studies are required to determine comparative efficacy with varying surgical techniques, and the ideal graft tension and degree of knee flexion during fixation have not yet been determined.     

Medial Patellofemoral Ligament Reconstruction: Indications,Technique, and Outcomes

The medial patellofemoral ligament is the primary static restraint to lateral patellar translation. It is injured in 96% to 100% of patellar dislocations that affect approximately 6 to 29 of 100,000 patients and is more common in patients younger than 20 years of age. Risk factors for patellar dislocation include patella alta, trochlear dysplasia, genu valgus, increased Q angle, and hyperlaxity. The treatment for patellar instability depends on the clinical and radiographic findings and can be nonoperative for first-time dislocations (bracing, proximal strengthening, and progressive return to sport) or operative for recurrent dislocations. It is critical for medial patellofemoral ligament reconstruction to reproduce the anatomy and isometry of the native ligament. Graft choice and methods of fixation are less critical to achieve successful outcomes. Studies have reported successful outcomes and improved Kujala scores, with recurrent instability ranging from 1% to 5%. Careful surgical technique can avoid complications, including fracture, graft failure, loss of range of motion, persistent anterior knee pain, medial instability, and recurrent instability. The role of the medial quadriceps tendon femoral ligament also should be considered more in future research.     

Medial patellofemoral ligament reconstruction: a novel approach

Recurrent patellar instability is common, and multiple procedures have been described for its treatment. Medial patellofemoral ligament reconstruction can be successful in patients who have an incompetent medial patellofemoral ligament or who have failed medial patellofemoral ligament repair and present with recurrent patellar instability. This article describes a novel approach to medial patellofemoral ligament reconstruction using a folded hamstring allograft with a new knotless suture anchor and bio-interference screw fixation. The principal advantage of this construct is the ability to definitively fix the medial patellofemoral ligament soft-tissue graft on the femur and provisionally fix the graft to the patella while assessing for reasonable medial patellofemoral ligament isometry throughout the arc of knee motion.     

A technique for reconstruction of the medial patellofemoral ligament

Additional medial patellofemoral ligament reconstruction was performed successfully on six consecutive patients with recurrent dislocation of the patella because of residual patellar instability after medial transfer of the tibial tubercle. A technique for medial patellofemoral ligament reconstruction is described, and complications and postoperative management are discussed. The reconstruction was performed using a double strand hamstring tendon graft in five patients and iliotibial allograft in one. Good stabilization of the patella was achieved in all six patients, resulting in improved confidence in higher levels of activity. The satisfactory outcome of additional medial patellofemoral ligament reconstruction suggests the possibility that the procedure may be part of the optional procedure in proximal realignment for recurrent dislocation of the patella.     

Anatomy of the knee extensor mechanism: correlation with patellofemoral arthrosis

The patellofemoral articulation is a common and significant source of disability and discomfort in the aging population. This study examined the anatomy of the knee extensor mechanism in patients having primary total knee arthroplasties, characterized the anatomic variations of the extensor mechanism, and correlated these findings with the location and extent of osteoarthritic change of the patellar undersurface. Sixty-two knees (57 patients) were evaluated prospectively. Specific characteristics that were analyzed included the mean Outerbridge grade for rating patellar cartilage degeneration and anatomic patterns of the extensor mechanism. Knees with a quadriceps tendon width at 2 and 5 cm above the patella that differed by less than 1 cm had more statistically significant patellar degeneration in all patellar locations than knees with tendon width differences greater than 1 cm. Anatomic variations, such as tendons with minimal increments in width in the proximal-distal direction, may be associated with an increasing amount of patellar arthrosis at the lateral facet, central ridge, and, most significantly, medial facet.     

A minimally invasive medial patellofemoral ligament arthroscopic reconstruction

The medial patellofemoral ligament reconstruction is recognized as a good choice for patients with recurrent patellar dislocation. Most techniques of the medial patellofemoral ligament reconstruction are open surgeries. Recently, we present a minimally invasive medial patellofemoral ligament arthroscopic reconstruction technique as a possible alternative method for recurrent patellar dislocation. The aim of the study was to describe a safe and effective technique to perform medial patellofemoral ligament reconstruction. The graft was prepared in shape to “Y.” Two 5-mm incisions were made in the skin above the medial edge of the patella. Two docking bone tunnels were drilled from medial edge to the center of the patella, mimicking the wide patellar insertion of the medial patellofemoral ligament, and a bone tunnel was made at the femoral insertion site. Two free ends of the graft were fixed into the patellar tunnels by lateral cortical suspension, and the folded end was fixed into the femoral tunnel by bioabsorbable interference screw. Average patellar tilt and the congruence angle were 30.7° ± 7.5° and 52.7° ± 7.3° and were reduced to 12.8° ± 0.9° and 2.3° ± 11.5° after treatment. The Kujala score was increased from 63.0 ± 9.0 to 91.0 ± 7.0. The minimally invasive medial patellofemoral ligament arthroscopic reconstruction in this paper seems to be helpful to increase safe of operation and treatment effect and reduce complications.     

Medial patellofemoral ligament reconstruction with gracilis autograft for patellar instability

We describe a technique for patellar stabilization by reconstruction of the medial patellofemoral ligament with the gracilis tendon. The tendon is anchored posteriorly on the soft tissue of the medial femoral epicondyle and anteriorly on the medial border of the patella. The plasty is completed by suture of the medial patellar wing. Inferior or medial transposition of the tibial tubercle may be associated. We have used this technique since 1995 for 145 knees with patellar instability. The small incisions have the advantages of minimally invasive surgery, particularly for the postoperative period and the cosmetic effect.     

Quadriceps tendon-patellar bone autograft for anterior cruciate ligament reconstruction: a technical note

The quadriceps tendon autograft can be used for primary and revision anterior cruciate ligament (ACL) reconstruction. Despite several successful clinical reports, graft fixation issues remain, and the ideal technique for fixation continues to be controversial. We present a technique of ACL reconstruction with quadriceps tendon autograft (QTA) using a patellar bone block. The tendon end is fixed in the femoral tunnel and the bone plug in the tibial tunnel using reabsorbable interference screws. The advantages of this technique are related to the increase in stiffness of the graft, the achievement of a more anatomic fixation, and a reduction in synovial fluid leakage.     

An alternative cruciate reconstruction graft: The central quadriceps tendon

The central quadriceps tendon, above the patella, is thicker and wider than the patella tendon. Using precise technique, one can obtain a tendon graft for cruciate reconstruction with 50% greater mass than a patellar tendon bone-tendonbone graft of similar width. The central quadriceps tendon graft may be harvested by a second surgeon while the first surgeon is simultaneously accomplishing notchplasty and tunnel placement for cruciate ligament reconstruction. Consequently, this cruciate ligament reconstruction graft offers time savings as well as greater tendon volume. The central quadriceps tendon graft is difficult to harvest, with significant risk of entering the suprapatellar pouch and losing knee distension during ACL reconstruction. By careful adherence to the technique described in this article, the surgeon can obtain this reconstruction graft safely. It is important to recognize the anatomic subtleties of the proximal patella, which include a curved proximal surface, dense cortical bone, and closely adherent suprapatellar pouch. Proper technique is of utmost importance in obtaining this tendon graft safely and efficiently.     

Medial Patellofemoral Ligament Reconstruction: A Novel Technique Using the Patellar Ligament

In patients with chronic patellofemoral instability, more than 2 episodes of dislocation, and an anterior tuberosity trochlear groove of less than 20 mm as measured on computed tomography or nuclear magnetic resonance imaging, we have developed a technique for medial patellofemoral ligament reconstruction that uses a medial strip of the patellar ligament (PL). The incision started proximally at the level of the superior margin of the patella, centrally between the patellar medial margin and the medial epicondyle. A descending incision was then made, directed toward the superomedial margin of the tibial tubercle. We performed a plane-by-plane dissection up to the peritenon of the PL. With an osteotome, we could remove a 2-cm bone fragment concerning the medial third of the distal insertion of the PL or keep the distal end free. Using a No. 11 scalpel blade, we carefully detached the PL from the patella up to the transition between the proximal third and medial third of the patella. We placed the stitches between the periosteum and the ligament using FiberWire absorbable threads (Arthrex, Naples, FL) to safely rotate the graft. After that, we dissected the medial capsule and approached the femoral medial epicondyle. Then we placed a Krackow suture in the free tendon end using absorbable threads or anchored the threads into 2 holes that were previously drilled, and we secured the end with an absorbable interference screw or anchors. The fixation should be performed with the knee at 15° to 30° of flexion. Then we sutured the distal edge of the vastus medialis muscle to the graft, which bestows a dynamic component upon the reconstruction, and we immobilized the knee with a removable brace.     

Implantless patellar fixation in medial patellofemoral ligament reconstruction

Purpose: The medial patellofemoral ligament (MPFL) acts as primary restraint to lateral patellar dislo cation and its rupture has been reported in almost all cases of acute patellar dislocation. Various surgical techniques have been described for MPFL reconstruction, using many femoral and patellar fixation techniques and different grafts. This article details our technique for MPFL reconstruction using sem itendinosus graft which avoids the use of implant at patellar end. Methods: Twenty patients (8 males and 12 females) with complaints regarding acute and chronic lateral patellar instability were evaluated and treated by MPFL reconstruction procedure. The mean age of patients was 21 years (range 17e34 years). MPFL reconstruction was performed using semitendinosus graft passing through two parallel, obliquely directed tunnels created in patella. Fixation of graft was done with an interference screw only at the femoral end. Mean follow-up period after intervention was 26.4 months (range 23-30 months). Results were evaluated using Kujala score. Results: All patients gained adequate patellar stability and full arc of motion. No incidence of patella fracture was noted. There were no postoperative complications related to the procedure. There was no recurrence of instability in patella at final follow-up. Conclusion: Passing the graft through the tunnels in patella without use of any implant has given excellent functional outcome and moreover has the advantages of less implant-related complications and cost-effectiveness.     

Patellaluxationen

Dislocation of the patella represents a frequent knee problem in childhood and adolescence. There are traumatic, recurrent, habitual and chronic forms. Many anatomical variations, which promote patellar dislocation, are known. The first traumatic dislocation is primarily treated conservatively with the exception of concomitant osteochondral fragments or very large soft tissue damage which justify surgical interventions. Recurrent, habitual and chronic dislocations are best cured surgically by vastus medialis advancement, reconstruction of the medial patellofemoral ligament, strengthening of the medial retinaculum together with a lateral release and by fixation of the patella using tendon grafts or medialisation of the insertion of the patellar ligament. To improve the femoropatellar groove by trochleoplasty is a different surgical concept. The long-term results following medialisation of the patellar ligament insertion or trochleoplasty are good with regards to patellar stability but mediocre in terms of avoiding degenerative changes in the patellofemoral joint.     

Die Rekonstruktion des medialen patellofemoralen Ligaments mit der getunnelten Semitendinosussehne

OBJECTIVE: Stabilization of the patella by reconstruction of the medial patellofemoral ligament. INDICATIONS: Chronic recurrent lateral dislocation or subluxation of the patella. Habitual lateral dislocation of the patella. CONTRAINDICATIONS: Primary dislocation of the patella. Genu valgum with a Q-angle > 15 degrees . Status following semitendinosus tendon transfer to reconstruct the anterior cruciate ligament. Joint infection. Neurogenic instability, ischiocrural muscle deficiency. SURGICAL TECHNIQUE: Division of the distal insertion of the semitendinosus muscle at the pes anserinus. Subligamentous tunneling at the proximal insertion of the medial collateral ligament. The distal end of the semitendinosus tendon is transferred through the subligamentous tunnel to the medial patellar margin. Fixation of the tendon to the medioproximal patellar margin by passing it through an oblique transpatellar drill hole. RESULTS: The patella was stabilized by dynamic reconstruction of the medial patellofemoral ligament in 14 patients with chronic recurrent or habitual lateral patellar dislocation. Ten patients were available for clinical follow-up assessment at an average of 13 months (8-27 months) postoperatively. The postoperative Kujala Index (maximum 100 points) increased on average from 56 to 95 points.     

内侧髌股韧带重建术治疗复发性髌骨脱位的疗效研究

目的探讨游离肌腱移植重建内侧髌股韧带的手术方法及治疗复发性髌骨脱位的疗效。方法自2006年6月至2012年7月收治复发性髌骨脱位患者共40例（47膝）,男10例（12膝）,女30例（35膝）,年龄7～51岁,平均19．4岁。全部经膝关节镜检最后确诊,其中43膝采用游离自体半腱肌,4膝采用异体肌腱,通过髌骨双隧道移植重建内侧髌股韧带,镜下动态调整移植肌腱的张力,使髌股关节对合达到正常,并用挤压螺钉将肌腱游离端固定在股骨止点。其中8例（10膝）同时行髌韧带止点内移术。结果有36例（42膝）患者获得随访,随访时间3—70个月,平均随访23个月。临床疗效评价包括髌骨主观稳定性评估、Lysholm膝关节评分及Insall疗效标准（1976年）。术后髌骨外推试验和恐惧试验均为阴性。手术前后Lysholm评分术前平均为（63．1±9．1）分,术后评分为（87．1±6．4）分,手术前后的差异有统计学意义（t=21．7,P〈0．05）。按Insall疗效标准,优良率为85．7％。结论采用以游离肌腱重建MPFL为主的综合术式治疗复发性髌骨脱位,手术效果满意。     

Spontaneous ruptures of the extensor system of the knee following joint replacement in patients with rheumatoid arthritis

Spontaneous ruptures of the quadriceps tendon and the patellar ligament following total knee arthroplasty in two patients with rheumatoid arthritis are reported. Degenerative and steroid-induced changes of tendinous tissue, circulation problems as well as mechanical changes to the patellofemoral joint by resurfacing the patella are discussed being possible causes of these complications of the extensor mechanism of the knee.     

Techniques of medial retinacular repair and reconstruction

Insufficiency of the passive patellar restraints results in lateral patellar instability by allowing excessive lateral displacement of the patella. Although the surgical approach to patellar instability traditionally has been to realign the dynamic elements (muscle forces) that pull the patella laterally, newer techniques have sought to restore the integrity of key medial passive (ligamentous) stabilizers. An increasing body of evidence indicates that the chief medial ligamentous restraint is the medial patellofemoral ligament. The current authors examine the principles of medial retinacular repair and reconstruction as they relate to patellar stability. Individual techniques and approaches are discussed, including primary repair with or without augmentation, and reconstruction using autogenous tendon, allografts, and synthetic graft materials. These procedures share the common objective of addressing the essential lesion in lateral patellar instability to restore the normal passive restraints against lateral patellar displacement.