Isolated reconstruction of the medial patellofemoral ligament with autologous quadriceps tendon

A Comparison of Proximal Patellar Realignment vs. Medial Patellofemoral Ligament Reconstruction: A Review of the Literature

» Patellar instability is challenging to address, and although there are many surgical options, proximal patellar realignment (PPR) and medial patellofemoral ligament (MPFL) reconstruction are both used-recently, the MPFL reconstruction has become more popularized.» Both procedures have demonstrated similar recurrent dislocation rates and rates of arthritic progression.» PPR is a cost-efficient procedure using just suture alone as compared with MPFL reconstruction, which uses different grafts and methods of fixation.» PPR has demonstrated durable results, with a lower overall complication rate, much of which is caused by the MPFL reconstruction having unique complications due to fixation methods.» The PPR is a beneficial procedure and should still be considered when dealing with patellar instability.

Minimal invasive medial patellofemoral ligament reconstruction using quadriceps tendon with de novo technique and arthroscopic guided: A case report

INTRODUCTION

Medial Patellofemoral ligament (MPFL) reconstruction, the primary procedure for restoring patellar stability and preventing further dislocation, has seen numerous methods and grafts. However, a consensus on the technique and graft remains elusive. This study introduces a novel approach to MPFL reconstruction, utilizing a unique combination of minimal invasiveness, de novo method, and arthroscopic guidance to harvest a quadriceps tendon (QT) graft without the need for a harvesting tool.

CASE ILLUSTRATION

A 37-year-old female presented to the emergency room with the chief complaints of left knee pain and swelling following the third spontaneous dislocation of the patella. The patient had a few episodes of locking sensation and instability of the left knee while walking, especially while climbing stairs. A knee MRI revealed MPFL tear in the left knee. A modified minimal invasive MPFL reconstruction technique was performed. The IKDC, Lysholm, and Modified Cincinnati scores improved significantly from preoperatively 48.3 %, 49 %, and 51 % to 89.7 %, 90 %, and 95 % consecutively. No recurrent patellar dislocations or swelling were reported during follow-up.

DISCUSSION

While quadriceps graft harvesting for MPFL reconstruction is typically highly invasive, using quadriceps tendons has consistently shown excellent outcomes. This study, however, takes it a step further by demonstrating that a minimally invasive procedure for harvesting quadriceps tendons, even without specialized instrumentation, can also yield excellent results.

CONCLUSION

MPFL reconstruction using superficial quadriceps tendon autograft can be achieved using a minimally invasive technique without the use of specialized instrumentation and has shown excellent knee functional improvement.

Medial Patellofemoral Ligament Reconstruction Using Pedicled Quadriceps Tendon Autograft Yields Similar Clinical and Patient-Reported Outcomes but Less Donor-Site Morbidity Compared With Gracilis Tendon Autograft

PURPOSE

To compare clinical and patient-reported outcome measures (PROMs) in patients with recurrent patellar dislocation after medial patellofemoral ligament (MPFL) reconstruction using either a gracilis tendon (GT) or quadriceps tendon autograft (QT).

METHODS

All MPFL reconstruction performed between 2017 and 2019 were reviewed retrospectively. Only patients with isolated MPFL reconstruction, without any major patellofemoral risk factors and a minimum follow-up of 24 months, were included in the study. Patients were matched with respect to sex, age, and body mass index. All patients were evaluated clinically and using PROMs.

RESULTS

A total of 64 patients with an average follow up of 28.7 ± 7.5 months were included in this study. The mean Kujala score (GT: 84.8 ± 12.9, QT: 88.9 ± 10.1), Lysholm score (GT: 89.4 ± 10.2, QT: 88.4 ± 5.0), and visual analog scale score for pain (GT: 1.9 ± 1.8, QT: 1.1 ± 1.3) did not significantly differ between both groups. Tegner activity level was significantly greater (P = .027) in the QT group (5.5 ± 1.9) compared with the GT group (4.6 ± 1.8), but within the minimal clinically important differences. Occasional patellar instability events, but no recurrent dislocation, were reported in 12.5% in the GT group and 6.3% in the QT group (P = .39). Of all patients, 90.6% in the QT and 68.8% in the HT group exceeded the PASS for the Kujala score (P = .06). Significantly more patients (59.4%) treated with GT reported donor-site morbidity in the form of sensitivity deficit at the lower leg compared with those treated with QT (3.1%, P = .001).

CONCLUSIONS

GT and QT MPFL reconstruction have comparable PROMs and patellar redislocation rates 2 years' postoperatively. Significantly more patients treated with GT reported lower-leg sensitivity deficit compared with those treated with QT.

LEVEL OF EVIDENCE

Level III, retrospective case-control study.

Stiffness and Instability After MPFL Reconstruction Using a Fluoroscopic Versus Open Technique to Localize the Femoral Attachment Site: A Systematic Review and Meta-analysis

Background

Open and fluoroscopic techniques have been described for localization of the femoral attachment site in medial patellofemoral ligament (MPFL) reconstruction. No study to date has evaluated if one technique is superior to another in terms of complications.

Purpose

To review the literature comparing clinical outcomes of MPFL reconstruction using the fluoroscopic versus open technique to localize the site of femoral graft placement.

Study Design

Systematic review; Level of evidence, 4.

Methods

A systematic literature review was performed via PubMed, Embase, and CINAHL to identify articles published between the inception of these databases and March 1, 2022, in accordance with the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. This search yielded 4183 publications for initial review. Studies with at least a 2-year follow-up and complete reporting of patient-reported outcomes, range of motion, recurrent instability, and/or complications (ie, stiffness, infection, persistent pain) were included. We excluded studies of patients with collagen disorders; revision surgeries; surgeries with concomitant procedures; synthetic MPFL reconstruction; MPFL repairs; combined open and radiographic technique; and case series that included <10 patients. A proportional meta-analysis was performed by calculating the pooled estimate of incidence with 95% CIs using a fixed-effects model with double arcsine transformation (Freeman-Tukey) for each type of surgical technique (fluoroscopic or open).

Results

A total of 29 studies met our inclusion criteria, of which 15 studies (566 patients) used the open technique and 14 studies (620 patients) used fluoroscopy. There were no significant differences between the open and fluoroscopic techniques in the incidence of postoperative apprehension (P = .4826), postoperative subjective instability (P = .1095), postoperative objective instability (P = .5583), reoperations (P = .7981), recurrent dislocation (P = .6690), or arthrofibrosis (P = .8118).

Conclusion

Both open and radiographic localization of the femoral graft position in MPFL reconstruction offer similar outcomes and rates of complications.

Medial patellofemoral ligament reconstruction using a digital tensiometer to determine graft tension: Surgical technique and mid-term follow-up

PURPOSE

The optimal method for achieving proper graft tension during patellofemoral ligament reconstruction is a topic of debate. In the past, a digital tensiometer was used to simulate the knee structure, and a tension of approximately 2N was identified as suitable for restoring the patellofemoral track. However, it is unclear whether this tension level is sufficient during the actual surgery. The objective of this study was to verify the efficacy of graft tension using a digital tensiometer for medial patellofemoral ligament (MPFL) reconstruction and to conduct a mid-term follow-up.

METHODS

The study enrolled 39 patients who had experienced recurrent patellar dislocation. Preoperative computed tomography scans and X-rays confirmed patellar instability, patellar tilt angle patellar congruence angle and the history of dislocation and patellar apprehension test. Knee function was evaluated using preoperative and postoperative Lysholm and Kujala scores.

RESULTS

The study included 39 knees, comprising 22 females and 17 males, with an average age of 21.10 ± 7.26. The patients were followed up for at least 24 months through telephone or face-to-face questionnaires. All patients had a preoperative history of ≥2 patellar dislocations, none of which were surgically treated. During surgery, all patients underwent isolated MPFL reconstruction and lateral retinacula release. The mean Kujala and Lysholm scores were 91.28 ± 4.90 and 90.67 ± 5.15, respectively. The mean PTA and PCA were 11.5 ± 2.63 and 2.38 ± 3.58, respectively. The study found that a tension of approximately 27.39 ± 5.57N (14.3-33.5N) was required to restore the patellofemoral track in patients with recurrent patellar dislocation. No patients required reoperation during the follow-up period. Overall, 36 out of 39 patients (92.31%) reported no pain when completing daily activities at the last follow-up.

CONCLUSION

In conclusion, a tension level of approximately 27.39 ± 5.57N is necessary to restore normal patellofemoral relationships during clinical practice, which indicates that using a tension of 2N is too low. The use of a tensiometer during patellofemoral ligament reconstruction is a more accurate and reliable surgical procedure for treating recurrent patellar dislocation.

Interference screws vs. suture anchors for isolated medial patellofemoral ligament femoral fixation: A systematic review

PURPOSE

The present study aimed to systematically review and compare 2 femoral autograft fixation techniques, namely, interference screws and suture anchors, for isolated medial patellofemoral ligament reconstruction in patients with recurrent patellofemoral instability at mid- to long-term follow-up.

METHODS

A literature search was performed in September 2020. All studies reporting the outcomes of primary isolated medial patellofemoral ligament reconstruction for recurrent patellofemoral instability were considered for inclusion. Only studies reporting the type of femoral autograft fixation under examination were considered. Studies reporting data from patients with elevated tibial tuberosity-tibial groove, patella alta, and/or Dejour's trochlear dysplasia types C and D, were not included. Only articles reporting data with a minimum follow-up period of 18 months were considered.

RESULTS

Data from 19 studies (615 patients) were retrieved. The overall age was 24.4 ± 6.7 years (mean ± SD). The mean follow-up was 46.5 ± 20.9 months. There were 76 patients in the anchor group and 539 in the screw group. Comparability was found with regard to age and follow-up duration between the 2 study groups. There was comparability between the Kujala, Lysholm, and Tegner scores at baseline. At the last follow-up, no worthy differences were found in terms of mean Kujala (+2.1%; p = 0.04), Lysholm (+1.7%; p = 0.05), and Tegner (+15.8%; p = 0.05) scores. Although complications occurred almost exclusively in the screw cohort, no statistically significant difference was found.

CONCLUSION

Femoral autograft fixation through interference screws or suture anchors report similar clinical scores and rate of apprehension test, persistent joint instability, re-dislocations, and revisions. These results must be interpreted within the limitations of the present study.

Complicações funcionais do tratamento da instabilidade patelar com reconstrução do ligamento femoropatelar medial com terço medial do tendão patelar com acompanhamento mínimo de 5 anos

Objetivo Avaliar complicações maiores após um mínimo de 5 anos de acompanhamento após luxação aguda ou recidivante da patela tratada com reconstrução do ligamento femoropatelar medial (LFPM) com terço medial do tendão patelar, com ou sem medialização da tuberosidade anterior da tíbia (TAT) associada.

Métodos Um total de 50 pacientes foram incluídos, com acompanhamento mínimo de 5 anos. Os pacientes foram avaliados em relação à ocorrência de complicações como rigidez articular, recidiva de luxação patelar ou instabilidade subjetiva relatada pelos pacientes, e incapacidade de retorno ao nível prévio de atividades físicas.

Resultados O acompanhamento médio foi de 8,9 ± 2,6 anos, com mínimo de 6 e máximo de 15 anos; 64% dos pacientes eram mulheres, com média de idade de 27 ± 11,2 anos; 24% dos pacientes foram submetidos a osteotomia da TAT para medialização concomitantemente; e 46% eram casos agudos. Foram constatados apenas 9 maus resultados (18%), todos decorrentes de recidiva da luxação (12%) e de queixa de instabilidade subjetiva (6%), ocorridos entre 36 e 60 meses de acompanhamento. Não ocorreram outras complicações. Dentre os maus resultados, cinco ocorreram em casos de luxação aguda, e quatro em casos recidivantes, e apenas um havia sido submetido a osteotomia da TAT.

Conclusão A reconstrução do LFPM com terço medial do tendão patelar, associada ou não à osteotomia de medialização da TAT, é uma alternativa no tratamento da instabilidade patelar aguda ou crônica, com falha de apenas 18% em acompanhamento mínimo de 5 anos. Além disso, é um tratamento seguro, sem apresentar outras complicações.

Prognostic factors for isolated medial patellofemoral ligament reconstruction: A systematic review

BACKGROUND

Evidence concerning the influence gender, age, and the time elapsed from the first dislocation to surgery in the outcomes of Medial Patella Femoral Ligament (MPFL) reconstruction are lacking. This systematic review was conducted to investigate whether patient characteristics have an influence in the clinical outcomes of MPFL reconstruction for patients with patellofemoral instability.

MATERIAL AND METHODS

This study followed the PRISMA guidelines. The main databases were accessed in February 2021. All the studies reporting outcomes of primary MPFL reconstruction in patients with recurrent patellofemoral instability were considered for inclusion. A multivariate analysis diagnostic tool was used to analyse the association between age, gender and time from injury to surgery and the surgical outcomes at last follow-up.

RESULTS

A total of 50 articles (2037 procedures) were included. The mean follow-up was 40.90 ± 24.8 months. The mean age was 23.6 ± 3.9 years. 64.3% (1309 of 2037 patients) were female. The mean time from injury to surgery was 64.5 ± 48.9 months. Women showed no statistically significant association with the Kujala score or complications. Older patients had a reduced risk to incur re-dislocations (P = 0.01) and revisions (P = 0.01). Longer time from injury to surgery was associated with greater risk to incur re-dislocations (P = 0.01), and with lower Kujala score (P < 0.0001). No other statistically significant association was evidenced.

CONCLUSION

The time span from the first patellar dislocation to the surgical reconstruction was a negative prognostic factor, while sex had no influence on surgical outcomes. The role of patients age on surgical outcomes remains unclear.

Isolated medial patellofemoral ligament reconstruction for recurrent patellofemoral instability: analysis of outcomes and risk factors

Background

The medial patellofemoral ligament (MPFL) is always damaged after patellar dislocation. In selected patients, MPFL reconstruction is necessary to restore a correct patellar tracking. Despite the large number of different techniques reported to reconstruct the MPFL, there is no consensus concerning the optimal procedure, and debates is still ongoing. The present study analysed the results after isolated MPFL reconstruction in patients with patellofemoral instability. Furthermore, a subgroup analysis of patients presenting pathoanatomical risk factors was made.

Methods

In November 2020, the main electronic databases were accessed. All articles reporting the results of primary isolated MPFL reconstruction for recurrent patellofemoral instability were considered for inclusion. Only articles reporting a minimum 12-month follow-up were eligible.

Results

Data from a total of 1777 knees were collected. The mean age of the patients involved was 22.8 ± 3.4 years. The mean follow-up was 40.7 ± 25.8 months. Overall, the range of motion (+ 27.74; P < 0.0001) and all the other scores of interests improved at last follow-up: Kujala (+ 12.76; P = 0.0003), Lysholm (+ 15.69; P < 0.0001), Tegner score (+ 2.86; P = 0.006). Seventy-three of 1780 patients (4.1%) showed a positive apprehension test. Thirty of 1765 patients (1.7%) experienced re-dislocations, while 56 of 1778 patients (3.2%) showed persisting joint instability. Twenty-five of 1786 patients (1.4%) underwent revision surgeries.

Conclusion

Isolated MPFL reconstruction for recurrent patellofemoral instability provides reliable surgical outcomes. Patients with pathoanatomical predisposing factors reported worse surgical outcomes.

Lateral retinacular release combined with MPFL reconstruction for patellofemoral instability: a systematic review

INTRODUCTION

The role of the lateral retinaculum in patellofemoral instability is still debated. Lateral retinacular release (LRR), has been extensively performed in combination with different surgical procedures, including reconstruction of medio-patellofemoral ligament (MPFL). Despite controversial indications, the results from these studies seem promising. The present study conducts a systematic review about current biomechanical and clinical evidence concerning the role of LRR in combination with MPFL reconstruction. We performed a comprehensive literature research, comparing the outcomes of MPFL reconstruction with and without LRR.

MATERIALS AND METHODS

This systematic review was conducted according to the PRISMA guidelines. The literature search was performed in August 2020. All articles describing the outcome of isolated MPFL reconstruction alone or in combination with a LRR in patients with recurrent patellofemoral instability were considered for inclusion. Only articles reporting data on patients with a minimum of 12-month follow-up were included. Only articles reporting quantitative data under the outcomes of interest were included.

RESULTS

A total of 63 articles were eligible for this systematic review, including 2131 knees. The mean follow-up was 40.87 ± 24.1 months. All scores of interests improved in favour of the combined group: Kujala + 3.8% (P = 0.01), Lysholm + 4.2% (P = 0.004), Tegner + 0.8 points (P = 0.04), IKDC + 9.8% (P = 0.02). The ROM was comparable between the two groups (P = 0.4). Similarity was found in terms of positivity to the apprehension test (P = 0.05), rate of complications (P = 0.1), re-dislocations (P = 0.8), and revision surgeries (P = 0.1).

CONCLUSION

There is no evidence that adding a lateral release impacts positively on the outcome of MPFL reconstruction.

LEVEL OF EVIDENCE

IV, Systematic review.

Recurrent patellofemoral instability rates after MPFL reconstruction techniques are in the range of instability rates after other soft tissue realignment techniques

PURPOSE

Recurrent patellofemoral instability is a common knee injury in skeletally immature patients. Many surgical techniques have been described in the literature, all with different success rates. Purpose of this study was to perform a systematic review and meta-analysis of the available literature to assess recurrent patellofemoral instability rates after surgical treatment using MPFL reconstruction techniques and other soft tissue realignment techniques in skeletally immature patients.

METHODS

PubMed, Embase, Web of Science, and The Cochrane Library were searched to identify all original articles concerning the surgical treatment for patellofemoral instability in skeletally immature patients and that reported post-operative recurrent patellofemoral instability rates. Subsequently a risk of bias assessment was conducted and a meta-analysis was performed on reported post-operative recurrent patellofemoral instability rates after MPFL reconstruction techniques and other soft tissue realignment techniques.

RESULTS

Of the 21 eligible studies (448 knees in 389 patients), 10 studies reported on MPFL reconstruction techniques using different grafts and fixation techniques and 11 reported on other soft tissue realignment procedures. In total, 62 of the 448 (13.8%) treated knees showed recurrent patellofemoral instability during follow-up. The overall pooled recurrent patellofemoral instability rate was estimated to be 0.08 (95% CI 0.02-0.16). For MPFL reconstruction techniques, the pooled recurrent patellofemoral instability rate was estimated to be 0.02 (95% CI 0.00-0.09). For the other soft tissue realignment techniques, the pooled rate was estimated to be 0.15 (95% CI 0.04-0.31). No statistically significant difference in recurrent patellofemoral instability rates between MPFL reconstruction techniques and other soft tissue realignment techniques were found (n.s.). There was a large variation in treatment effects over different settings, including what effect is to be expected in future patients.

CONCLUSION

This systematic review and meta-analysis found that recurrent patellofemoral instability rates after MPFL reconstruction techniques are in the range of instability rates after other soft tissue realignment techniques. The clinical relevance of this study is that it provides clinicians with the best currently available evidence on recurrent patellofemoral instability rates after surgical treatment for patellofemoral instability in skeletally immature patients.

LEVEL OF EVIDENCE

IV.

Isolated versus combined medial patellofemoral ligament reconstruction for lateral instability of the patella

INTRODUCTION

Medial patellofemoral ligament reconstruction (MPFLR) is regularly combined with a tibial tuberosity transfer (TTT) in cases of recurrent patellar instability with underlying structural deformity. However, these indications for a TTT have recently come into question. This study aimed to assess the traditional indications by comparing the outcomes of isolated and combined MPFLR for the treatment of recurrent lateral patellar dislocation.

METHODS

A systematic review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Included studies were those which reported the outcomes of either isolated or combined or both MPFLR. Studies were required to report at least one of the following: redislocation rate, revision due to instability, or the Kujala score.

RESULTS

We found no difference between isolated and combined MPFLR in terms of redislocation ( p = 0.48), revisions due to instability ( p = 0.36), positive apprehension tests ( p = 0.25), or the Kujala score ( p = 0.58). Combined reconstruction presented more complications compared to isolated procedures ( p = 0.05). Subgroup analysis revealed no significant difference between studies investigating isolated medial patellofemoral ligament reconstruction MPFLR performed in patients with normal tibial tuberosity-trochlear groove (TT-TG) distances only or in patients with both normal and elevated TT-TG distances.

CONCLUSIONS

According to the published data, there is no difference in outcomes between isolated and combined MPFLR. Underlying structural deformity did not demonstrate any significant effect on the success of the isolated MPFLR. Although there are definite indications for combined reconstruction, the current evidence suggests that our inclusion criteria may not be entirely correct. Further study is required to clarify and refine the true indications for combined MPFLR.

LEVEL OF EVIDENCE

III, meta-analysis of nonrandomized studies.

Single- versus double-bundle patellar graft insertion for isolated MPFL reconstruction in patients with patellofemoral instability: a systematic review of the literature

INTRODUCTION

The MPFL reconstruction is performed either via a single-bundle (SB) or double-bundle (DB) procedure. The purpose of this study is to perform a systematic review comparing SB versus DB graft for recurrent patellofemoral instability, to summarize current evidence, and to clarify the role of both techniques. We focused on clinical scores, physical examination, complications, revision surgeries, and failures.

MATERIAL AND METHODS

In May of 2019 the main online databases were accessed. All the clinical studies treating isolated MPFL reconstruction for patellofemoral instability through a single and/or double-bundle graft were enrolled in the present systematic review. Only articles reporting primary isolated MPFL reconstruction, reporting a minimum of 12-months follow-up were considered for inclusion.

RESULTS

The scores of interest were in favour of the DB cohort: Kujala (+ 3.2, P = 0.03), Lysholm (+ 5.1, P = 0.001), Tegner (+ 0.3, P = 0.2), IKDC (+ 5.4, P = 0.01), VAS (+ 0.8, P = 0.3), ROM (+ 9.96, P = 0.04). In the DB graft, a reduction of overall complications (OR 0.59; P = 0.1), further surgeries (OR 0.64; P = 0.12) and re-dislocations (OR 0.61; P = 0.16) was observed. The SB group reported a reduction in the post-operative apprehension test (OR 2.42; P = 0.24).

CONCLUSION

Current study support the use of double-bundle tendon graft for isolated MPFL reconstruction in selected patients with recurrent patellofemoral instability.

Medial patellofemoral ligament reconstruction using an autograft or allograft for patellar dislocation: a systematic review

Purposes

The purpose of this study is to review the use of an allograft or autograft in medial patellofemoral ligament (MPFL) reconstruction.

Materials and methods

Various electronic databases were searched for relevant articles published from January 2000 to September 2017 that evaluated clinical outcomes of MPFL reconstruction using an autograft or allograft. Data search, extraction, analysis, and quality assessments were performed based on Cochrane Collaboration guidelines.

Results

The study of 21 autografts and one allograft was included in this review. Although direct comparative studies were unavailable, the Kujala score and subjective results were reported in the majority of these studies. While the use of an autograft for MPFL reconstruction yielded satisfactory clinical outcomes with few perioperative complications, no new outcome has been drawn from the use of allografts.

Conclusions

Although many studies have shown favorable clinical results for MPFL reconstruction using an autograft, the clinical results of MPFL reconstruction using an allograft have not yet been sufficient to achieve meaningful clinical results due to low levels of evidence. Direct comparisons were not conducted because there were very few studies on allografts; thus, further research in this area should be performed in the future.

Electronic supplementary material

The online version of this article (10.1186/s43019-019-0008-0) contains supplementary material, which is available to authorized users.

Medial patellofemoral ligament (MPFL) reconstruction using quadriceps tendon autograft provides good clinical, functional and patient-reported outcome measurements (PROM): a 2-year prospective study

PURPOSE

The medial patellofemoral ligament (MPFL) is the most important ligamentous stabilizer preventing lateral patella dislocation. Numerous surgical procedures for MPFL reconstruction have been described in the literature. The aim of this study was to investigate the clinical, functional and patient-reported (PROM) outcomes 2 years after minimally invasive MPFL reconstruction performed using an autologous strip of the quadriceps tendon.

METHODS

Thirty-six patients (38 knees) were included in the study. For MPFL reconstruction, a partial thickness autologous quadriceps tendon graft was used. All patients were evaluated clinically and with patient-reported outcome questionnaires including the Tegner, Lysholm and Kujala scores as well as a visual analogue scale (VAS) for pain preoperatively and at 6, 12 and 24 months postoperatively. A functional Back-in-Action (BIA) test battery, including a total of seven stability, agility and jumping tests, was performed on 19 (50%) patients at the final follow-up. One patient was lost to follow-up at 24 months.

RESULTS

The mean age at the time of operation was 25.2 ± 6.1 years. No redislocations occurred during the period of investigation. The mean Lysholm score improved significantly from 79.3 ± 16.1 preoperatively to 83.2 ± 14.4 at 6 months, 88.1 ± 11.3 at 12 months and to 90.0 ± 9.6 at 24 months follow-up. No change throughout the study period was observed for the median Tegner Activity Score (median 6). The mean Kujala score increased from a preoperative value of 82.0 ± 12.4, to 84.5 ± 8.4 at 6 months, and 88.2 ± 5.8 at 12 months up to 88.7 ± 4.5 at 24 months follow-up. A total of 77.8% of the performed functional BIA tests were equal to or above the norm for patients of the corresponding ages and activity levels.

CONCLUSIONS

Minimally invasive MPFL reconstruction with a partial thickness strip of quadriceps tendon is a safe and effective treatment for patellofemoral instability. Good clinical, functional and subjective results were observed at the 2-year follow-up.

LEVEL OF EVIDENCE

Prospective cohort study, non-randomized, Level IV.

Medial patellofemoral ligament reconstruction in children: A comparative randomized short-term study of fascia lata allograft and gracilis tendon autograft reconstruction

BACKGROUND

Many surgical procedures have been described to treat recurrent patellar dislocation, but none of these techniques has been successful in all patients. The goal of the study was to evaluate the results of medial patellofemoral ligament reconstruction in children. Two operative procedures were evaluated; a fascia lata allograft and an autologous gracilis graft.

METHODS

Forty-four children (27 girls and 17 boys) between 13 and 17 years of age with unilateral recurrent patellar dislocation underwent medial patellofemoral ligament (MPFL) reconstruction. Patients were operated in two orthopedic centers. The 1st group contained 22 patients and surgery was performed using a fascia lata allograft. In the 2nd group of patients which also contained 22 children and autologous gracilis graft was used. The mean age of the patients was 14.9 years and the mean follow-up was 24 months. Preoperatively, all patients were evaluated clinically (Kujala score questionnaire) and radiologically. The same evaluation was used 18 to 30 months postoperatively to estimate the results of our treatment.

RESULTS

In 1st group of children operated with cadaver allografts, the Kujala score significantly improved from 73.91 points preoperatively to 94.50 points postoperatively (P < .001). The average duration of operating procedure was 1 hour and 35 minutes. As shown by subjective symptoms, the results in 95% of patients were rated as good or very good. All children returned to full activity. Similar results were obtained in patients in 2nd group, where MPFL was reconstructed with ipsilateral gracilis tendon. Kujala score increased from 70.77 points preoperatively to 94.32 postoperatively (P < .001). Our results were estimated as good or very good in 93% of patients. All patients that were operated returned to full activity. However, median duration of operation was longer and lasted 1 hour and 55 minutes.

CONCLUSIONS

Both techniques were effective in the short-term (18-30 months) in treatment of recurrent patellar dislocation. The use of cadaver allograft spares the hamstring muscles and reduces the time of surgery. Therefore, such study appears to be useful because it provides valuable information that would help to guide treatment of this condition in children. Level of evidence II-2.

Surgical Management of Patellofemoral Instability in the Skeletally Immature Patient

Compared with skeletally mature patients, skeletally immature patients are at a higher risk of acute traumatic patellar dislocation. Surgical treatment is the standard of care for patients with recurrent instability and requires important and technically challenging physeal considerations. Physeal-sparing medial patellofemoral ligament reconstruction is the treatment of choice for these patients, replacing older nonanatomic extensor mechanism realignment techniques. Implant-mediated guided growth is an important adjunct to correct genu valgum angular deformities that contribute to patellar instability. Patient-specific surgical techniques and proper surgical indications are crucial for successful outcomes.

Quadriceps Tendon Autograft Medial Patellofemoral Ligament Reconstruction

PURPOSE

Critically evaluate the published literature related to quadriceps tendon (QT) medial patellofemoral ligament (MPFL) reconstruction.

RECENT FINDINGS

Hamstring tendon (HT) MPFL reconstruction techniques have been shown to successfully restore patella stability, but complications including patella fracture are reported. Quadriceps tendon (QT) reconstruction techniques with an intact graft pedicle on the patella side have the advantage that patella bone tunnel drilling and fixation are no longer needed, reducing risk of patella fracture. Several QT MPFL reconstruction techniques, including minimally invasive surgical (MIS) approaches, have been published with promising clinical results and fewer complications than with HT techniques. Parallel laboratory studies have shown macroscopic anatomy and biomechanical properties of QT are more similar to native MPFL than hamstring (HS) HT, suggesting QT may more accurately restore native joint kinematics. Quadriceps tendon MPFL reconstruction, via both open and MIS techniques, have promising clinical results and offer valuable alternatives to HS grafts for primary and revision MPFL reconstruction in both children and adults.

Mechanical Analysis of Extra-Articular Knee Ligaments. Part two: Tendon grafts used for knee ligament reconstruction

OBJECTIVES

The aim of this study was to provide information about the mechanical properties of grafts used for knee ligament reconstructions and to compare those results with the mechanical properties of native knee ligaments.

METHODS

Eleven cadaveric knees were dissected for the semitendinosus, gracilis, iliotibial band (ITB), quadriceps and patellar tendon. Uniaxial testing to failure was performed using a standardized method and mechanical properties (elastic modulus, ultimate stress, ultimate strain, strain energy density) were determined.

RESULTS

The elastic modulus of the gracilis tendon (1458±476MPa) (P<0.001) and the semitendinosus tendon (1036±312MPa) (P<0.05) was significantly higher than the ITB (610±171MPa), quadriceps tendon (568±194MPa), and patellar tendon (417±107MPa). In addition, the ultimate stress of the hamstring tendons (gracilis 155.0±30.7MPa and semitendinosus 120.1±30.0MPa) was significantly higher (P<0.001, respectively P<0.05), relative to the ITB (75.0±11.8MPa), quadriceps tendon (81.0±27.6MPa), and patellar tendon (76.2±25.1MPa). A significant difference (P<0.05) could be noticed between the ultimate strain of the patellar tendon (24.6±5.9%) and the hamstrings (gracilis 14.5±3.1% and semitendinosus 17.0±4.0%). No significant difference in strain energy density between the grafts was observed.

CONCLUSIONS

Material properties of common grafts used for knee ligament reconstructions often differ significantly from the original knee ligament which the graft is supposed to emulate.