Recurrent patella dislocation is a well-recognized complication after primary dislocation of the patellofemoral joint. We propose that acute surgical management of the injury minimizes this risk. Between February 2006 and August 2010 47 patients (49 knees) with a mean age of 17.9 (range 12–31) at the time of surgery who sustained a patellofemoral joint dislocation for the first time were treated with an acute repair of the medial patellofemoral ligament. Patients presenting to our fracture clinic following a primary lateral dislocation of the patella were investigated with an MRI scan and with consent, proceeded to have an examination under anaesthesia and arthroscopy of the injured knee. An easily dislocatable patella in the presence of a confirmed medial patellofemoral ligament rupture was the indication for open repair. All patients treated surgically were followed up for a period of 24–72 months where the primary outcome measure was further dislocation. An evaluation of symptoms, functional recovery, restoration of range of movement and patient satisfaction was made supported by the Lysholm knee score. Our results confirm that acute repair of the medial patella femoral ligament in selected patients reduces the risk of further dislocations and results in a overall good functional outcome and patient satisfaction with minimal complications

Purpose of Study: The role of surgery in the treatment of acute patella dislocation has always been controversial with procedures falling in and out of popularity. Since the Medial Patellofemoral ligament was first described in 1979, its importance as a prime patella stabiliser has been defined, and procedures for its repair and reconstruction have been described. We believe that the MPFL has a pivotal role in the stability of the patella, and is disrupted in all patients with acute patella dislocation. Failure to address this will inevitably lead to ongoing patellofemoral symptoms. Methods: We summarise the current literature detailing the anatomy and biomechanical properties of the native as well repaired MPFL. We present our own experience of treating acute patella dislocations by repair of the Medial Patellofemoral Ligament, in acute cases. A lesion can occur anywhere along its length from the superomedial patella to a point superoposterior to the adductor tubercle. The technique of repair has to address the site of primary disruption, as well as any associated intraarticular knee injuries. Results: In one series we have shown that of 13 patients who presented with acute patella dislocation, 10 had an MRI proven lesion of the MPFL and went on to have an open repair which reconstituted patella stability. Conclusion: A lesion of the MPFL is the primary pathology in acute patella dislocation, and we believe that this lesion warrants surgical intervention to avoid progressive symptoms

Purpose: To evaluate the patients who underwent acute surgical repair of medial patellofemoral ligament following first lateral dislocation of patella. Methods: Twenty four patients with mean age 19 yrs (12–41) who underwent acute repair of MPFL were reviewed. The mean follow-up was 14 months (2–35 months). All patients had MRI scan preoperatively and most of them were operated within two weeks of injury. Patients were evaluated clinically and Kujala and modified Lysholm were recorded. None of these patients had further dislocations and all had negative patellar apprehension tests. The mean Kujala and modified Lysholm scores were above 85. Conclusion: Our results strongly support that in selected patients acute repair of MPFL prevents further dislocations and early return to sporting activities. The long term results are to be evaluated

Aim. This study looks for correlation between pre-operative MRI and intra-operative surgical findings regarding the site of medial patellofemoral ligament (MPFL) rupture in first time patella dislocaters with the aim of confirming the reliability of this modality of imaging. Methods. A retrospective analysis of all patients who were referred for MRI following patella dislocation was performed. The surgical and MRI findings of those who subsequently underwent MPFL repair were compared to look for any correlation. Results. 41 patients were first time patella dislocators and 38 had MPFL rupture diagnosed on MRI. Of these 19 progressed to surgical intervention and 17 had adequate data available from the notes to permit comparison. All of the MPFLs ruptured at the patella insertion. In 76.5% (13/17) of patients the site of MPFL rupture was correctly identified on MRI scan. Of those that were discordant, 3/4 had the site of rupture identified as the femoral insertion on MRI and on 1/4 had an MRI suggestive of rupture at both the femoral and patella insertions. Conclusion. MPFL rupture is common in first time dislocations occurring in 93% of this cohort on MRI. There was a predominance for patella insertion rupture in our study which contrasts with the majority of the published literature. By correlating surgical and radiological findings we can conclude that while MRI can accurately diagnose MPFL rupture at the patella insertion it is less accurate in identifying rupture at the femoral insertion

The tensile strength of the medial patellofemoral ligament (MPFL), and of surgical procedures which reconstitute it, are unknown. Ten fresh cadaver knees were prepared by isolating the patella, leaving only the MPFL as its attachment to the medial femoral condyle. The MPFL was either repaired by using a Kessler suture or reconstructed using either bone anchors or one of two tendon grafting techniques. The tensile strength and the displacement to peak force of the MPFL were then measured using an Instron materials-testing machine. The MPFL was found to have a mean tensile strength of 208 N (SD 90) at 26 mm (SD 7) of displacement. The strengths of the other techniques were: sutures alone, 37 N (SD 27); bone anchors plus sutures, 142 N (SD 39); blind-tunnel tendon graft, 126 N (SD 21); and through-tunnel tendon graft, 195 N (SD 66). The last was not significantly weaker than the MPFL itself

The medial patellofemoral ligament is commonly torn in first patella dislocation and according to the literature occurs most frequently at the femoral insertion. As research has demonstrated the MPFL to be a primary soft tissue stabilizer of the patella there has been increased interest in acute repair of the ligament with the aim of reducing the risk of recurrent dislocation. MRI is generally used pre op to identify the site of rupture allowing planning of the surgical repair, however there is currently no published data regarding the correlation between surgical and MRI findings to confirm the reliability of this modality of imaging. A retrospective analysis of all patients who were referred for MRI following patella dislocation was performed. The surgical and MRI findings of those who subsequently underwent MPFL repair were compared to look for any correlation. 41 patients were first time patella dislocators and 38 had MPFL rupture diagnosed on MRI. Of these 19 progressed to surgical intervention and 17 had adequate data available from the notes and to permit comparison. All of the MPFLs ruptured at the patella insertion. In 76.5% (13/17) of patients the site of MPFL rupture was correctly identified on MRI scan. Of those that were discordant 3/4 had the site of rupture identified as the femoral insertion on MRI and on 1/4 the MRI suggested rupture at both the femoral and patella insertions. MPFL rupture is common in first time dislocations occurring in 93%% of this cohort. There was a clear predominance patella insertion rupture in our study which contrasts with the majority of the published literature. By correlating surgical and radiological findings we can conclude that while MRI can accurately diagnose MPFL rupture at the patella insertion but it is less accurate in identifying rupture at the femoral insertion

Recurrent patellar dislocation is a relatively common disorder in young patients. Historically, treatment options have been based on the underlying disorder predisposing the patient to the dislocation. This has resulted in various soft tissue reefing procedures, patella tendon realignment procedures and boney realignment procedures. Further research has shown that the medial patellofemoral ligament (MPFL) is the primary restraint to lateral patella subluxation and dislocation. Many authors have published their successful treatment of recurrent patella dislocation by reconstruction of the medial patellofemoral ligament. The most widely used is autologous semitendinosis tendon grafts, as well as synthetic materials, and MPFL reconstructions may be combined with boney procedures. Varieties of fixation techniques have been described involving both the patella and femoral sides. We present a technique of MPFL reconstruction using the autologous ipsilateral quadriceps tendon. Our technique avoids the morbidity associated with semitendinosis graft harvesting and the drill holes in, and potential resulting fracture of, the patella. The technique is also simple and is associated with decreased procedure costs. We present the technique and a series of 6 patients (7 knees) with follow up ranging from 8 months to 9 years. The average age of patients at the time of surgery 16–28 years (mean = 20years). There have been no redis-locations. The median Kujala patellofemoral knee score at follow up was 97 out of 100 (Range 69–100). The results compare very favourably to published results using other techniques. Our technique of reconstructing the MPFL is reliable, produces good results using an objective knee score, and is cost effective

Introduction. Patellar stability is an important component for a correct kinematic behaviour of the knee that depends on several factors such as joint geometry, muscles strength and soft tissues actions. Patellofemoral (PF) maltracking can results in many joint disorders which can cause pain and mobility alterations. The medial patellofemoral ligament (MPFL) is an important stabilizing structure for the patellofemoral joint. The aim of this study was to analyze patellofemoral kinematics with particular attention to the contribution of MPFL on patella stability. Methods. Using a navigation system PF kinematics during passive flexion/extension movements with quadriceps loaded at 60N, was recorded on 6 cadavers in three different anatomical conditions: intact knee, MPFL cut and MPFL reconstructed with graft. Test on patella was conducted without lateral force and with applied lateral force (25N). Tilt and lateral shift was evaluated in both cases at 0°. 30°, 60°and 90° of flexion. Results. Test results without applied force showed that there is no statistical difference between intact knee and MPFL cut conditions in all ranges of flexion, both for medio-lateral shift and tilt, which have low values. In test with applied force a significative increase of patellar lateral translation at 30° (16,8 ± 13,4 mm) and 60° (18,6 ± 6,4 mm) was found. MPFL reconstructed knee behaviour was not statistically different to intact knee both for tilt and medio-lateral shift. Therefore lateral translation was widely reduced with the graft. Conclusions. Without applied stress intact knees and MPFL cut knees behave in the same way. In applied load conditions MPFL cut knees show wide lateral translation in respect to intact and reconstructed knees. MPFL reconstructed knees are similar to intact knee therefore MPFL restraint is significant only in stress conditions. This may indicate that the MPFL is a aponeurosis, with an active role under stress, but low role during neutral knee flexion

Introduction. The medial patellofemoral ligament (MPFL) is the main stabilizer of the patella and therefore mostly reconstructed in the surgical correction of patellofemoral dislocation. Various biomechanical and clinical studies have been conducted on MPFL reconstruction, while the patellofemoral contact pressure (PFCP) which is indicated as one of the predictors of retropatellar osteoarthritis was neglected. Therefore, the aim of this study was to investigate how different MPFL reconstruction approaches affect PFCP. Material & Methods. After radiographic examination and preparation six human cadaveric knee joints (52.1 ± 8.4yrs) were placed in a 6-DOF knee simulator. Three flexion-extension cycles (0–90°) were applied, while the extensor muscles (175N) and an axial joint load (200N) were simulated. PFCP was measured in knee flexion of 0°, 30° and 90° using a calibrated pressure measurement system (K-Scan, Tekscan Inc., USA). The following MPFL conditions were examined: native (P. nat. ), anatomical reconstruction (P. a. ), proximal and distal patellar single-bundle reconstruction (P. p. , P. d. ), proximal and ventral femoral reconstruction (F. p. , F. v. ). The cohesive gracillis graft of each knee was used for MPFL reconstruction. Further, the effect of three different graft pre-tensioning levels (2N, 10N, 20N) on the PFCP were compared. Nonparametric statistical analysis was performed using SPSS (IBM Inc., USA). Results. In 0° knee flexion median PFCP of the native state (P. nat. =0.46MPa) was significantly higher (p=0.04) compared to the ventral femoral fixation state (F. v. =0.24MPa). No significant differences were observed in 30° knee flexion. In 90° knee flexion PCFP of both femoral reconstructions (F. p. =1.26MPa, F. v. =1.12MPa) were significantly higher (p<0.04) compared to the native state (P. nat. =0.43MPa). Graft pre-tensioning had no significant impact (p>0.27) on the PFCP in 0°, 30° and 90° knee flexion for all pre-tensioning levels. Discussion. We investigated the PFCP of different MPFL reconstructions and compared them during continuous joint motion from 0° to 90° knee flexion. While a non-anatomical graft fixation on the femoral side leads to an excessive increase of PFCP (293%), a non-anatomical positioning on the patellar side only showed minor impact on the PFCP. An anatomical MPFL reconstruction showed comparable PFCP to the native joint. In contrast to the literature, we did not find a significant influence of graft pre-tensioning from 2N up to 20N on the PFCP. With respect to all study findings we would recommend to use the anatomical footprints for MPFL reconstruction and a moderate graft pre-tensioning of 2N

INTRODUCTION: The techniques to stabilize the patella can be divided into two groups: the first group seeks to change the direction of the extensor mechanism in order to medialize the extending force vector of the quadriceps muscle, e.g. by a distal medialization of the tibial tuberosity or a proximal realignment; the second seeks to reconstruct the medial patellofemoral ligament (MPFL). The goal of this study was therefore to measure changes in patellofemoral kinematics in the intact, MPFL deficient knee, after medial transfer of the tibial tuberosity, after proximal realignment as well as after reconstruction of the MPFL. METHODS: Eight fresh frozen right knee specimens were mounted in a knee simulator in which isokinetic flexion-extension motions were simulated. Extension cycles were simulated from 120° flexion to full knee extension with an extension moment of 31 Nm. Movement of the patella relative to the femur was measured using an ultrasound based 3D motion analysis system (Zebris, Isny, Germany). During the first test cycles, patellar movement under intact knee conditions were measured, while a constant 100 N laterally oriented force was applied by means of a steel cable attached to the patella. Subsequently, patellar movement was again measured after: transecting the MPL (deficient knee), performing a medialization of the tibial tuberosity, after reconstruction of the transected MPL using a semitendinosus autograft and after proximal realignment. RESULTS: The patella of the intact knee moved along a medial path with a maximum attained position of 8.8 mm at 25° of knee flexion. The patella of the deficient knee moved up to 4.6 mm (p=0.04) in the medial direction at maximal extension at 30° of knee flexion. After medial transfer of the tibial tuberosity patellar movement reached a maximum medial position of 12.8 mm (p=0.04) at 22° of knee flexion with the laterally oriented force. With a reconstructed MPL, the patella attained a maximum medial position 14.8 mm (p=0.04) at 24.0° of knee flexion. Following proximal realignment, the patella moved on a medial, but significant (p=0.03) different path up to 13.8 mm medially at 30° of knee flexion. In addition, following medialization of the tibial tuberosity and proximal realignment, the center of the patella was significantly (p=0.03) more internally rotated (tilted) than the physiologic patella. DISCUSSION: The shape of the movement curves after the stabilizating procedures resulted in a medialization relative to intact and deficient conditions. With the reconstructed medial patellofemoral ligament, the patella moved along the most medially oriented path with physiologic tilting. The results suggest that a semi-tendinous autograft can provide sufficient stabilization to prevent lateral displacement or subluxation with physiologic patellar tilt

Purpose The tensile strength of the isolated Medial Patellofemoral Ligament (MPFL) is unknown. The strength required of reparative or reconstructive procedures to re-constitute this major patella stabilising structure are therefore unknown. Method 10 fresh cadaveric right (6 female 4 male) knees, mean age 71.6 (SD 16.6) years, were prepared to isolate the MPFL between the patella and the Medial Femoral Condyle (MFC). The tensile strength and mode of failure were then determined. The ligament was then repaired using a suture and the tensile strength of this determined. The ligament was then reconstructed in three ways including: Biodegradable corkscrew anchors and two tendon techniques with interference screws. One method used a blind tunnel into the MFC, while the other passed through a tunnel in the femoral condyles. Both methods passed through tunnels in the patella. Results The mean ultimate tensile strength of the isolated MPFL was 207.9 (SD 90.1) Newtons. Seven specimens failed through a mid-substance tear while three pulled off the MFC. The mean strength of the suture repair was 36.7 (SD 26.5) Newton. The biodegradable bone anchor gave a mean strength of 142.3 (SD 38.5) Newton. The blind tunnel hamstring reconstruction’s had a mean strength of 126 (SD 20.8) Newton. The double tunnel hamstring reconstruction’s failed at a mean of 195.0 (SD 65.6) Newton. Conclusion The force required to rupture an isolated MPFL appears to be approximately 210 Newton. Suture repair is insufficient to reconstitute this. Reconstruction with bone anchors or hamstring tendon techniques come close to this

Purpose. Investigate the functional outcome of medial patellofemoral ligament (MPFL) surgery for patella instability. Compare functional outcome of direct MPFL repair and reconstruction using hamstring graft. Methods. All patients that underwent MPFL surgery for patella instability between 2007-2010 were retrospectively identified from operative records. Patients were divided based on whether they underwent direct repair of MPFL, or reconstruction using hamstring graft. The Kujala scoring questionnaire for patellofemoral disorders (max score 100) was used to assess their functional outcome following surgery. Results. 33 patients were identified, 11 were not suitable for inclusion in the study. The remaining 22 patients had a total of 25 operations for patella stabilisation (3 bilateral). Average age of patient at time of surgery was 21 (15-33), 15 male and 7 female. 17 had direct repair of MPFL, 8 had reconstruction using hamstring graft. Of the 8 reconstructions 6 were primary procedures and 2 were for failed direct repair due to further traumatic injury. Mean follow-up period was 17 months (6-43). Mean Kujala score overall 91.6, mean score for reconstruction group 93.2, direct repair score 90.7. Total number of further patella dislocations in the repair group was 1/17 (5.9%). No patients in the reconstruction group reported any further patella dislocations following their surgery. Conclusion. Both direct repair and reconstruction of MPFL for patella instability demonstrate high functional outcome at short/mid-term follow up. Our high success rate in direct MPFL repair, good functional outcome and low re-dislocation rate is better than that quoted in the current literature

Recurrent patellar dislocation is a relatively common disorder in young patients. Historically, treatment options have been based on the underlying disorder predisposing the patient to the dislocation. This has resulted in various soft tissue reefing procedures, patella tendon realignment procedures and boney realignment procedures. Further research has shown that the medial patello-femoral ligament (MPFL) is the primary restraint to lateral patella subluxation and dislocation. Many authors have published their successful treatment of recurrent patella dislocation by reconstruction of the medial patellofemoral ligament. The most widely used is autologous semitendinosis tendon grafts, as well as synthetic materials, and MPFL reconstructions may be combined with boney procedures. Varieties of fixation techniques have been described involving both the patella and femoral sides. We present a technique of MPFL reconstruction using the autologous ipsilateral quadriceps tendon. Our technique avoids the morbidity associated with semitendinosis graft harvesting and the drill holes in, and potential resulting fracture of, the patella. The technique is also simple and is associated with decreased procedure costs. We present the technique and a series of six patients (seven knees) with follow up ranging from eight months to nine years. The average age of patients at the time of surgery 16 to 28 years (mean = 20 years). There have been no redislocations. The median Kujala patellofemoral knee score at follow up was 97 out of 100 (Range 69–100). The results compare very favorably to published results using other techniques. Our technique of reconstructing the MPFL is reliable, produces good results using an objective knee score, and is cost effective. Seventy staff members participated from a potential pool of approximately one hundred staff on duty at the time. Of the seventy staff who participated in this research project a total of three staff members were within 50 mls of the correct amount for each of the three samples. Overall staff were very poor at estimating blood loss. Staff working in the operating theatre, no matter what their affiliation or years of experience, are not accurate when estimating blood loss spilt into a patients bed. A tool that aids in blood loss estimation is a valuable addition to the theatre resource manual

Purpose of the study: From a biomechanical view, the medial force stabilising the patella is assured for 50 to 60% by the medial patellofemoral ligament (MPFL). The purpose of this cadaver study was to present a precise description of the anatomic features of the MPFL concerning its femoral insertion, its relations with the oblique vastus medialis (OVM) and its relation with the medial collateral ligament (MCL) in order to optimise surgical reconstruction. Material and methods: This cadaver study was performed on 23 knees from fresh cadavers. All measures were made knee flexed 30° by the same operator. Insertions of the OVM on the MPFL, when present, were identified. The length of the zone of reflexion was recorded. For these measurements, a orthonormal landmark centred on the femoral insertion of the MPFL was established. This landmark was used to position the medial epicondyle and the adductor tubercle for each knee. Results: The MPFL was found in all 23 knees (100%); the length of the MPFL was 57.7±5.8 mm; its femoral insertion measured 12.2±2.6 mm (8–136); its patellar insertion measured 24.4±4.8 mm. A junction between the OVM and the MPFL was found for all 23 knees (100%). This zone appeared to be a veritable reflexion zone with the OVM fibres arching over the MPFL fibres for a length of 25.7±6 mm. Discussion: Our study confirms the constant presence of the MPFL, observed in 100% of the knees studied. During the reconstruction of the MPFL, the key point is the position of the femoral insertion of the ligament, in order to restore the native femoral insertion of the MPFL surgically and thus attempt to recreate perfect isometry of the graft. The graft must be positions 10 mm posteriorly to the medial epicondyle and 10 mm distally to the adductor tubercle. In our cadaver the MPFL, the main medial stabilising force of the patella was a constant finding, always located in the second thickness of the medial plane of the knee. Conclusion: We detailed the native femoral insertion of the MPFL and described its relations with the medial femoral epicondyle and the adductor tubercle using an orthonormal landmark. Long-term function of the graft depends on proper positioning

We investigated the clinical outcome of a reconstructive procedure of the medial patellofemoral ligament for the treatment of habitual or recurrent dislocation of the patella in four children (6 knees), with a minimum follow-up of four years. The technique involves transfer of the tendon of semitendinosus to the patella using the posterior one-third of the femoral insertion of the medial collateral ligament as a pulley. There was no recurrence of dislocation after surgery. The mean Kujala score at follow-up was 96.3 points. Radiological assessment showed that the congruence angle, the tilt angle and the lateral shift radio were restored to normal. The lateral and medial stress shift ratios and the Insall-Salvati ratio remained abnormal. We conclude that this technique can be recommended for the treatment of habitual or recurrent patellar dislocation in children, although hypermobility and patella alta are not fully corrected

Abstract

Aims

The aim of this study was to establish consensus statements on the diagnosis, nonoperative management, and indications, if any, for medial patellofemoral complex (MPFC) repair in patients with patellar instability, using the modified Delphi approach.

Hypermobility is an acknowledged risk factor for patellar instability. In this case control study the influence of hypermobility on clinical outcome following medial patellofemoral ligament (MPFL) reconstruction for patellar instability was studied.

A total of 25 patients with hypermobility as determined by the Beighton criteria were assessed and compared with a control group of 50 patients who were matched for age, gender, indication for surgery and degree of trochlear dysplasia. The patients with hypermobility had a Beighton Score of ≥ 6; the control patients had a score of < 4. All patients underwent MPFL reconstruction performed using semitendinosus autograft and a standardised arthroscopically controlled technique. The mean age of the patients was 25 years (17 to 49) and the mean follow-up was 15 months (6 to 30).

Patients with hypermobility had a significant improvement in function following surgery, with reasonable rates of satisfaction, perceived improvement, willingness to repeat and likelihood of recommendation. Functional improvements were significantly less than in control patients (p < 0.01).

Joint hypermobility is not a contraindication to MPFL reconstruction although caution is recommended in managing the expectations of patients with hypermobility before consideration of surgery.

Patellofemoral instability is common injury and proximal soft tissue stabilisation via MPFL reconstruction or imbrication is the mainstay of treatment. The contribution of certain pathoanatomies to the failure of patellofemoral stabilisation is unknown. The purpose of this study was to analyse the failure rate of patellar stabilisation procedures in a large cohort as measured by re-dislocation of the patella. A secondary purpose was to identify the pathoantomical features that may have predisposed these patients to failure.

Between May 2008 and March 2014, 207 MPFL reconstructions and 70 MPFL imbrications were performed by a single surgeon. Post-operative assessment included clinical examination to assess the integrity of the MPFL graft, plain radiographs and the Banff Patellofemoral Instability Instrument (BPII), a disease-specific outcome measure. Failures were identified and risk factors including trochlear dysplasia, patella alta, generalised ligamentous laxity (GLL), femoral tunnel position and rotational abnormalities were evaluated as contributing factors.

There were 48 male and 178 female patients. The mean duration of follow-up was 24.1 months (SD 9.4, range 12–74). The average age at time of surgery was 24.81 years (SD 8.87, range 50.35–8.99). The average BMI was 23.75 (SD 3.62, range 36.70–14.90). There were 10 failures in the MPFL reconstruction group (4.8%), 1 male and 9 females. Femoral tunnel position was assessed in relation to Schottle's point as good or excellent in all 10 cases. In terms of pathoanotomy, 8/10 failures had high-grade trochlear dysplasia, 1/10 had patella alta, 6/10 had a Beighton score of >/= 4, and 3/10 had clinically significant rotational abnormalities of the lower extremity. The primary cause attributed to the 10 failure cases was trauma in two, trochlear dysplasia in three, rotational abnormalities in one, combined femoral anteversion and GLL in two, and combined trochlear dysplasia and GLL in two. There were 13 failures in the MPFL imbrication group (18.6%), 2 males and 11 females. Among these failures, 4/13 had high-grade trochlear dysplasia, 3/13 had patella alta, 10/13 had a Beighton score of >/= 4, and one had clinically significant rotational abnormalities of the lower extremity. The primary pathology that was considered to contribute to the imbrication failure cases was trochlear dysplasia in four, generalised ligamentous laxity in six, rotational abnormalities in one, patella alta with trochlear dysplasia in one, and generalised ligamentous laxity with trochlear dysplasia in one. Prior to surgical failure the mean BPII score for the failure group was 71.5/100, compared with 74.6/100 for the remainder of the cohort.

MPFL reconstruction is highly successful surgical procedure for stabilising the unstable patella with a failure rate of only 4.8%. Higher failure rates are seen in patients undergoing imbrication of the MPFL compared to a reconstruction. Pathoanatomies that contribute to failure vary between patients with the most common being trochlear dysplasia and generalised ligamentous laxity.

Patellar instability is a common clinical problem affecting a young, active population. A large number of procedures have been described to treat patellar instability. We present the clinical results in a case series of 25 medial patellofemoral ligament reconstructions in 21 patients with up to 30 months follow-up (mean 7.3 months).

Reconstruction was performed using either the gracilis tendon (6 cases) or semitendinosus tendon (19 cases) autograft. At follow-up the Tegner activity scores, objective knee function, complications and reoperations were assessed.

No patella re-dislocations were observed. Five patients (20%) required a manipulation under anaesthetic but subsequently regained a satisfactory range of motion. Two patients (8%) had post operative complications. One patient developed a post operative infection which required a washout and one patient developed a neuroma related to the hamstring harvest site which was excised. Both subsequently returned to work with a full range of motion.

Medial patellofemoral reconstruction with both gracilis and semitendinosus tendon graft provided good postoperative patellar stability restoring the primary soft tissue restraint to pathological lateral patellar displacement.