Anatomic medial patellofemoral ligament reconstruction using patellar suture anchor fixation for recurrent patellar instability

Purpose

The purpose of this study was to prospectively evaluate clinical and radiographic outcomes following anatomic medial patellofemoral ligament (MPFL) reconstruction using patellar suture anchor fixation for recurrent patellar instability.

Methods

Twenty patients (20 knees) were enrolled in this study. The median age was 21 years, and the median follow-up was 34.5 months. Reconstruction was performed using a hamstring autograft fixed with two suture anchors at native patellar site of the MPFL. No patient had undergone additional medial tibial tuberosity transfer. Clinical scores (Kujala, Lysholm, and Tegner score) and apprehension test were completed preoperatively and at the follow-up. Preoperative and follow-up radiographic assessments included modified Insall-Salvati ratio, congruence angle, and lateral patellofemoral angle.

Results

The preoperative Kujala and Lysholm scores were 52.6 ± 12.4 and 49.2 ± 10.7, and at follow-up visits, corresponding values were 90.9 ± 4.5 (p < 0.001) and 90.9 ± 5.2 (p < 0.001). Tegner score increased from 3.0 (range 1–4) to 5.0 (range 4–7) (p < 0.001). The apprehension test was positive in all patients preoperatively, but only positive in one patient at follow-up. All radiographic assessments were significantly improved; modified Insall-Salvati index (from 1.75 to 1.65) (p = 0.002), congruence angle (from 6.3° to ?7.0°) (p < 0.001), and lateral patellofemoral angle (from 2.1° to 4.9°) (p = 0.008). No patient experienced a patellar fracture or redislocation.

Conclusion

These results are comparable to those of bone tunnel techniques reported in the literature. This study shows that anatomic MPFL reconstruction using two suture anchors is a reliable treatment option.

Level of evidence

Case series with no comparison group, Level IV.     

Medial patellofemoral ligament reconstruction in patients with lateral patellar instability and trochlear dysplasia

BACKGROUND: Reconstruction of the medial patellofemoral ligament has been proven to restore stability in patients with lateral patellar instability. No study to date has examined the results in a patient population with the predisposing factor of femoral trochlear dysplasia. HYPOTHESIS: Reconstruction of the medial patellofemoral ligament restores stability and provides pain relief in patients who have lateral patellar instability in association with trochlear dysplasia. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: Thirty-four patients with chronic patellar instability and trochlear dysplasia were treated with medial patellofemoral ligament reconstruction using an adductor tendon autograft, bone-quadriceps tendon autograft, or bone-patellar tendon allograft. All patients were evaluated preoperatively and postoperatively with Kujala, Lysholm, and Tegner scores at a minimum of 24 months. RESULTS: Thirty-four patients were followed for a mean of 66.5 months (range, 24-130 months) after surgery. Kujala scores improved from 53.3 to 90.7, Lysholm scores improved from 52.4 to 92.1, and Tegner activity scores improved from 3.1 to 5.1. All improvements were highly statistically significant (P < .001). No statistical difference was found between the postoperative Lysholm, Kujala, and Tegner scores and the degree of dysplasia, graft type, or degree of symptoms. There were 85.3% and 91.1% good and excellent results based on Kujala and Lysholm scores, respectively. No recurrent dislocations have occurred. CONCLUSION: Medial patellofemoral ligament reconstruction provides excellent long-term pain relief and functional return in patients with patellar instability and femoral trochlear dysplasia. In addition, reconstruction prevents recurrent dislocation, despite the diminished bony constraint of a dysplastic trochlea.     

Medial patellofemoral ligament reconstruction with hanger lifting procedure

Medial patellofemoral ligament (MPFL) reconstruction has become a common surgical procedure in the treatment of recurrent dislocation of the patella. A technique of MPFL reconstruction with the “hanger lifting procedure” using extra-articular arthroscopy is presented. After conventional intra-articular arthroscopy, an incision about 1 cm long is made at the superomedial edge of the patella. A bone tunnel is created with a guide pin and overdrilling method, from this portal to the subcutaneous surface of the patella. Using a semi-loop-shaped hanger, the harvested Gracillis tendon is passed through the bone tunnel using a passing pin. Under extra-articular arthroscopy with the “hanger lifting procedure”, this tendon is then led back to the superomedial portal. Both ends of the Gracillis tendon are then led to the femoral fixation site posterosuperior to the medial epicondyle with a tendon passer, and fixed by an absorbable interference screw. This procedure can be performed under a minimum incision using a hanger, but control radiographs should be taken to confirm appropriate placement of bone tunnels.     

Medial patellotibial ligament (MPTL) reconstruction for patellar instability

Purpose

To evaluate mid-term clinical and radiographic outcomes after an original medial patellotibial ligament reconstruction in patients with patellar dislocation.

Methods

Twenty-nine knees (27 patients, 8 males and 19 females) treated for patellar dislocation with medialization of the patellar tendon medial third combined with medial and lateral release were evaluated clinically and radiographically at a mean follow-up of 6.1 ± 2.5 years. Trochleoplasty was performed in case of severe flat trochlea (6 knees, 21 %). Aetiology of patellofemoral instability was traumatic in 6 (21 %) and atraumatic in 23 (79 %) knees. The mean age at first dislocation was 19.2 ± 10.1 years. WOMAC, subjective and objective IKDC, Kujala, VAS for pain, Tegner activity and EQ-5D scores were used. Anteroposterior, lateral and 30° axial views were performed for radiographic monitoring.

Results

There was a significant improvement of all clinical scores and significant reduction in knee pain. Twenty-four knees (83 %) were normal or nearly normal by objective IKDC score at final follow-up. Radiographs showed a higher incidence of patella alta and flat trochlea in the atraumatic group. Severe signs of patellar osteoarthritis were found in 1 knee (3 %). A higher body mass index (BMI) was correlated with worse pre-operative scores. Four knees (14 %) were considered failures (2 further dislocations, 2 revision surgeries). The overall survival rate at 6 years was 0.811.

Conclusions

The presented techniques produced good clinical and radiographic results at mean 6.1 years follow-up, with 14 % failures. Signs of patellofemoral dysplasia were found in patients with atraumatic patellar dislocation. BMI was related to worse pre-operative clinical status.

Level of evidence

Retrospective study, Level IV.     

Medial patellofemoral ligament reconstruction for patellar maltracking following total knee arthroplasty is effective

Purpose

Maltracking of the patella after total knee arthroplasty (TKA) remains a well-recognized problem. The medial patellofemoral ligament (MPFL) has shown to be important for patellar stabilization and reconstructions of the MPFL have already shown excellent functional outcomes for patellar instability of the native knee. Nevertheless, there is only limited literature on using an MPFL reconstruction for correction of patellar maltracking after TKA. In this retrospective study, a consecutive case series was evaluated.

Methods

Between 2007 and 2010, nine patients (nine knees) with anterior knee pain and symptomatic (sub)luxations of the patella after primary or revision TKA were treated by reconstruction of the MPFL in combination with a lateral release. In two cases, an additional tibial tuberosity transfer was performed, due to insufficient per-operative correction. Pre-operative work-up included a CT scan to rule out component malrotation and disorders in limb alignment. Pre- and post-operative patellar displacement and lateral patellar tilt were measured on axial radiographs. Clinical outcome was evaluated using the visual analogue scale (VAS) satisfaction, VAS pain, dislocation rate and Bartlett patella score.

Results

Median patellar displacement improved from 29 mm (0–44) to 0 mm (0–9) post-operatively. Median lateral patellar tilt was 45° (23–62) pre-operative and changed to a median 15° (?3 to 21) post-operative. Median VAS satisfaction was 8 (5–9) and only one patient reported a subluxing feeling afterwards. The Bartlett patella score displayed a diverse picture.

Conclusions

Patellar maltracking after primary or revision TKA without malrotation can effectively be treated by MPFL reconstruction in combination with a lateral release. Only in limited cases, an additional tibial tuberosity transfer is needed.

Level of evidence

IV.     

Outcomes of medial patellofemoral ligament reconstruction for patellar instability: a systematic review

It has been suggested that in the majority of patellar dislocation cases the medial patellofemoral ligament (MPFL) is disrupted. Accordingly several authors over the past decade have recommended repair or reconstruction of the MPFL to reduce the high incidence of recurrent dislocation. The purpose of this review was to determine whether MPFL reconstruction is a suitable procedure with regards to clinical and radiological outcomes for patients with patellar instability. A literature search using the electronic databases AMED, British Nursing Index, CINAHL, the Cochrane database, EMBASE, ovid Medline, Physiotherapy Evidence Database (PEDro), PsycINFO, Pubmed and Zetoc were performed from their inception to May 2007. All English language, human subject clinical papers reporting outcomes following MPFL reconstruction were included. Eight papers, collectively assessing 186 MPFL reconstructions, were finally included for review. Three reviewers independently assessed the methodological quality of each of the studies using the CASP appraisal tool. When analysed, it would appear that MPFL reconstruction may provide favourable clinical and radiological outcomes for patellar instability patients. However, following a critical appraisal of these papers a number of methodological weaknesses were identified including recruiting small samples, not controlling for confounding variables, and providing limited statistical analysis of results. Future study is recommended to address these methodological flaws, in addition to beginning to assess the effectiveness of this procedure, in different patient groups.     

Dynamic versus static reconstruction of the medial patellofemoral ligament for recurrent lateral patellar dislocation

Purpose

To compare clinical and radiological outcomes of static and dynamic medial patellofemoral ligament (MPFL) reconstruction techniques.

Methods

In a retrospective, matched-paired, cohort analysis, 30 patients surgically treated for recurrent lateral patellar dislocation were divided into two groups of 15 patients matched for inclusion and exclusion criteria. The static technique group underwent rigid fixation of the gracilis tendon at the anatomic femoral MPFL insertion and the superomedial border of the patella; the dynamic technique group underwent detachment of the gracilis tendon at the pes anserinus with fixation to the proximal medial patellar margin via tunnel transfer obliquely through the patella. Kujala, Lysholm, and Tegner scores; pain level; and pre- and postoperative radiographic changes of patellar height, patellar tilt, and bisect offset were compared.

Results

No significant between-group differences were found in mean Kujala, Tegner, Lysholm, or visual analogue scale scores or radiographic parameters. One case of resubluxation was observed in the dynamic group. All but one patient in each group would have been willing to undergo the procedure again.

Conclusions

Both techniques provided satisfactory short-term outcomes.

Level of evidence

III.     

Recurrent patellar dislocation after medial patellofemoral ligament reconstruction

We report on three cases of recurrent lateral patellar dislocation following a medial patellofemoral ligament (MPFL) reconstruction for patellar instability. In all three cases, an isolated MPFL reconstruction was performed with a double autogenous gracilis graft. The patellar fixation was done through bone tunnels. All three patients presented with a definite moderate to severe traumatic episode resulting in a recurrent patella dislocation and a transverse avulsion fracture at the medial rim of the patella. All three were treated by an open reduction and internal fixation with good results. No complication or recurrent dislocations occurred. We suggest that this complication is caused by the original underlying pathology such as dysplastic trochlea, abnormal TT–TG, patella alta and hyperlaxity, resulting a greater reliance upon the reconstructed MPFL for patellar stability. When subjected to a severe stress, the graft, which is stronger and stiffer than the original MPFL, will cause a fracture through the medial edge of the patella. This weak area results from the previous drill holes, which act as stress risers.     

Medial patellofemoral ligament reconstruction using a hamstring graft

Recurrent lateral dislocation of the patella has been historically treated with a combination of multiple techniquesincluding lateral release, proximal realignment, medial reefing, and distal realignment. Poor-quality medial retinacular tissues and nonanatomic surgical attempts to restrain the patella may contribute to notable problems with redislocation and anterior knee pain. Recent biomechanical studies have identified the functional importance of the medial patellofemoral ligament as the primary restraint to lateral translation of the patella. A technique of reconstruction of this ligament with a single semitendinosis autograft, which provides a sturdy check-rein to lateral translation, is described. The authors' current indications for this procedure are (1) the recurrent lateral patellar dislocations in a patient with poor-quality medial soft tissues and no definable MPFL, and (2) the failure of previous proximal or proximal and distal realignment procedures with continued medial functional deficiency.     

Medial patellofemoral ligament reconstruction: indications and technique

Lateral instability of the patella is a common problem that often requires reconstruction of the proximal soft tissue restraints. The medial patellofemoral ligament (MPFL) has been demonstrated to be the major soft tissue stabilizer to prevent abnormal lateral displacement of the patella. In this chapter we will discuss the anatomy, biomechanics, indications, and technique for surgical reconstruction of the medial patellofemoral ligament.     

The case for advancement and repairof the medial patellofemoral ligament in patients with recurrent patellar instability

In much of the literature about patellar instability, the role of the passive medial patellar stabilizers traditionally has been ignored or afforded only passing comment. But excessive passive lateral patellar mobility must be considered an essential element in the majority of patients with recurrent acute lateral patellar instability. In patients who have sustained patellar dislocation, numerous authors have shown excessive lateral or total mediolateral patellar mobility compared with normal controls. Clinical and laboratory magnetic resonance evidence suggests that the medial retinaculum shows typical patterns of injury in many cases of acute lateral patellar dislocation. Residual laxity of these soft tissue restraints can be sufficient to allow recurrent lateral instability of the patella after the initial dislocation event. Several studies suggest that the medial patellofemoral ligament (MPFL) is the primary passive soft tissue restraint to lateral patellar displacement. These studies have shown promising evidence that repair and/or advancement of the MPFL is capable of restoring normal lateral patellar mobility in cadaver specimens. If the MPFL is repaired effectively in patients who have sustained retinacular injury in the setting of patellar dislocation, then it should reduce the risk of recurrent patellar instability. In this article, the senior author's surgical technique for advancement and repair of the MPFL is presented. Postoperative rehabilitation is also discussed.     

Medial patellofemoral ligament anatomy: implications for its surgical reconstruction

The purpose of the present study, based on 23 cadaveric knees, was to perform a detailed anatomical analysis of the medial patellofemoral ligament (MPFL), especially its femoral attachment, its relationships with the vastus medialis obliquus (VMO) and the medial collateral ligament, with the objective of improving its surgical reconstruction. The femoral insertion of the MPFL was defined using an orthonormal frame centered on the middle of the femoral MPFL insertion. The whole measurements were taken using a millimetric compass with a precision of ±1 mm. The MPFL was always observed, its length was 57.7 ± 5.8 mm, the junction between the VMO and the MPFL always present measured 25.7 ± 6.0 mm. When it comes to MPFL reconstruction, the key point is its positioning in the femoral insertion because it is this insertion that is going to restore isometry. By using the orthonormal frame it has to be positioned 10 mm behind the medial epicondyle and 10 mm distal to the adductor tubercle.     

Medial patellofemoral ligament reconstruction with lateral soft tissue release in adult patients with habitual patellar dislocation

Purpose

Habitual dislocation of the patella is a rare condition and a treatment plan has not yet been established. The purpose of this case report is to assess the effectiveness of medial patellofemoral ligament (MPFL) reconstruction for treating adults with habitual dislocation.

Methods

We performed MFPL reconstruction in two women with habitual patellar dislocation. Patient 1 was 39 and Patient 2 was 57 years old. Both patients frequently experienced giving way and received surgical treatments that involved extensive release of tight lateral soft tissue followed by medial patellofemoral ligament reconstruction using semitendinosus tendon.

Results

Follow-ups at 5 years (Patient 1) and 3 years (Patient 2) after operation confirmed no recurrent dislocation in either patient and significantly improved knee function.

Conclusions

Although a longer-term follow-up is necessary, MPFL reconstruction combined with lateral soft tissue release seems a promising treatment for habitual dislocation of the patella in adults.

Level of evidence

V.     

Effects of medial patellofemoral ligament reconstruction on patellar tracking

Purpose  

Medial patellofemoral ligament (MPFL) reconstruction has been performed to treat recurrent patellar dislocation. However, the effects on patellar tracking have not been well documented, particularly in patients. The purpose of this study is to compare patellar tracking pattern and chondral status at MPFL reconstruction with those at second-look arthroscopy.     

部分腓骨长肌腱重建内侧髌股韧带治疗复发性髌骨脱位

目的 探讨关节镜辅助下自体部分腓骨长肌腱移植重建内侧髌股韧带(medial patellofemoral ligament,MPFL)治疗复发性髌骨脱位的疗效.方法 2009年5月-2010年4月治疗46例53膝复发性髌骨脱位患者,关节镜下进行外侧髌股支持带松解后,采用自体部分腓骨长肌腱游离移植重建MPFL,调整移植肌腱在不同角度下屈伸活动时的张力,关节镜下观察髌骨运动轨迹和股骨滑车与髌骨的对应关系,然后采用可吸收界面螺钉将肌腱端固定于股骨内侧髁的骨道内,同时行胫骨结节内移抬高术.了解髌股关节的稳定情况、脱位复发、患膝主观症状以及患肢整体功能康复情况.结果 术后随访平均18个月(12～24个月),膝关节稳定性增加,髌骨脱位无复发.恐惧试验阴性,髌骨轴位X线片和CT示髌股关节解剖关系恢复正常.手术前后Kujala 髌骨稳定度问卷评分术前(54.6±5.4)分,术后(92.3±8.9)分(t =55.41,P＜0.01).所有患者运动能力均较术前有所改善.术后CT检查对比发现,髌骨与股骨滑车适配角从术前的(27.8±8.1)°改善为(2.3±9.4)°(t=20.87,P＜0.01).肌腱供区踝关节活动良好,功能没有影响.结论 关节镜下外侧髌股支持带松解与自体部分腓骨长肌腱移植重建MPFL,结合胫骨结节内移抬高术能够有效治疗复发性髌骨脱位,并且避免了膝关节周围切取肌腱的潜在并发症.