Objective To review the influencing factors of medial patellofemoral ligament (MPFL) reconstruction for patellar dislocation. Methods The literature of MPFL reconstruction for patellar dislocation at home and abroad in recent years were summarized and analyzed. Results The influencing factors such as the location of the femoral insertion point, the tension and the fixed angle of the grafts, the dysplasia of the femoral trochlear before operation, the abnormal tuberositas tibiae-trochlear groove value, the high position of the patellar, and the tilting angle of the patellar, are all the factors affecting the effectiveness of MPLF reconstruction. Conclusion During MPFL reconstruction, the surgical techniques and elimination of other factors that caused patellar instability need to be focused in order to reduce the complications and operation failure.
Objective To investigate the effectiveness of arthroscopic medial retinaculum plication (MRP) for acute patellar dislocation (APD) in adolescents. Methods Between March 2007 and June 2011, 24 adolescent patients suffering from APD were treated by arthroscopic MRP. There were 14 males and 10 females, aged 8-18 years (mean, 12.7 years). The location was the left knee in 16 cases and the right knee in 8 cases. Injury was caused by sports in 19 cases, by traffic accident in 4 cases, and by heavy bruising in 1 case. The duration from injury to operation was 3 to 21 days with an average of 7.8 days. The results of floating patella test and dislocation apprehension test were both positive. MRI examination showed the arthroedema in all cases; associated injuries included medial retinaculum injury in 20 cases, medial patellar injury in 8 cases, and meniscus tear in 5 cases. Results All incisions healed by first intention without complication of infection or neurovascular injury. All the patients were followed up 12-36 months (mean, 14.6 months). Only 2 patients suffered from patellar re-dislocation at 4 months and 6 months after operation respectively. The knee joint activity returned to normal at 12 months. The Lysholm, Kujala, and International Knee Documentation Committee (IKDC) scores at 3 and 12 months after operation were significantly higher than those before operation (P lt; 0.05), and the scores at 12 months were significantly higher than those at 3 months (P lt; 0.05). Conclusion Treatment of APD with arthroscopic MRP has the advantages of minor trauma and good knee functional improvement. The technique can decrease incidence of patellar re-dislocation in adolescent.
Objective To investigate the procedure and effectiveness of medial patellofemoral l igament (MPFL) reconstruction for the treatment of recurrent patellar dislocation. Methods Between June 2005 and September 2007, 29 patients with recurrent patellar dislocation underwent MPFL reconstruction with allograft semitendinosus or allograft anterior tibial is tendon. There were 6 males and 23 females with an average age of 20.3 years (range, 13-45 years). The patients sufferedfrom 2-10 times patellar dislocation preoperatively. The average time between last dislocation and surgery was 43.9 months (range, 1-144 months). CT scan was performed to measure the tibial tuberosity-trochlear groove distance (TT-TG). The femoral tunnel was made at the origin of MPFL insertion, just inferior to the medial epicondyle. The double L-shape patellar tunnels were made on the medial rim of patella with 4.5 mm in diameter. The loop side of the graft was fixed with a bioabsorbable interference screw in the femoral tunnel both ends of the graft. For the TT-TG was more than 20 mm, a modified Elmsl ie-Trillat osteotomy was performed to correct the distal al ignment of patella. The arthroscopic examination was also performed for loosebody and lateral retinacular release. Results Twenty-seven patients were followed up 45.5 months on average (range, 40-67 months). No recurrent dislocation or subdislocation occurred. All the patients showed negative apprehension test at 0° and 30° flexions of knee. The range of motion of knee restored normal 1 year after operation. The Kujala score was improved from 72.03 ± 17.38 preoperatively to 94.10 ± 7.59 postoperatively, and Lysholm score was improved from 72.65 ± 14.70 to 95.44 ± 6.25, both showing significant differences (P lt; 0.05). The Tegner score was decreased from 5.25 ± 1.83 preoperatively to 4.33 ± 1.00 postoperatively, showing no significant difference (t=1.302, P=0.213). In patients whose TT-TG was more than 20 mm, TTTG was decreased from (23.38 ± 3.70) mm to (16.88 ± 5.92) mm at last follow-up, showing significant difference (t=2.822,P=0.026). Conclusion The technique of MPFL reconstruction is an effective surgical procedure for the treatment of recurrent patellar dislocation, which can improve the patella stabil ity and knee function.
ObjectiveTo explore the clinical effects of combined operation involving tibial tubercle distalization for the recurrent patellar dislocation with patella alta.MethodsBetween April 2010 and May 2016, 14 cases of recurrent patellar dislocation with patella alta were treated with combined operation involving tibial tubercle distalization. There were 5 males and 9 females with an average age of 18.5 years (range, 13-26 years). The left knee was involved in 9 cases and the right knee in 5 cases. The patella had dislocated 3.3 times on average (range, 2-5 times). The interval between the first dislocation and admission was 19.7 months on average (range, 4-60 months), and the main symptoms were knee pain and limited knee movement. Preoperative X-ray films, CT, and MRI examinations of knee joint showed that the epiphyseal plate closed in all patients. Of all patients, 3 patients had avulsion fracture of the inner edge of patella, and 2 patients had free body in articular cavity. The tibial tuberosity-trochlear groove (TT-TG) distance, patellar-trochlear-groove distance, Caton-Deschamps index, knee range of motion (ROM), Lysholm score, International Knee Documentation Committee (IKDC) score, Kujala score, and Tegner score were compared pre- and post-operation.ResultsAll patients had primary wound healing. All patients were followed up 24-72 months with an average of 34.6 months. X-ray film and CT examination showed that the patellar dislocation was corrected and the osteotomy of the tibial tubercle healed with an average healing time of 3.8 months (range, 3-5 month). At 1 day and 1 year after operation, the TT-TG distance, patellar-trochlear-groove distance, and Caton-Deschamps index showed significant differences when compared with preoperative values (P<0.05), but there was no significant difference between 1 day and 1 year after operation (P>0.05). At the 1 year and 2 years after operation, the knee ROM, Lysholm score, IKDC score, Kujala score, and Tegner score showed significant differences when compared with preoperative values (P<0.05), and there was no significant difference between the 1 year and 2 years after operation (P>0.05).Conclusion Combined operation involving tibial tubercle distalization is a safe and reliable method, which has satisfactory short-term effectiveness for the recurrent patellar dislocation with patella alta.
Objective To evaluate an improving operative procedure and the cl inical results of arthroscopically assisted treatment for acute patellar dislocation. Methods Between April 2006 and March 2009, 22 patients (25 knees) with primary acute complete dislocation of the patella underwent an improving arthroscopic operation, release of lateral retinaculum and suture of medial capsule and retinaculum structure. There were 5 males and 17 females with an average age of 23.6 years (range, 14-34 years). Three patients had bilateral procedure. Eleven left knees and 14 right knees were involved. The disease duration was 1-10 days with an average of 5.9 days. All patients had lateral dislocation; of them, 14 patients showed reduction without treatment, and 8 patients showed dislocation at admission and were given close manipulative reduction. The results were positive for apprehension test in all patients with the l imitation of passive motion and for Ballottable Patella Sign in 15 cases. Lysholm score, visual analogue scale (VAS) score, and Insall scale were adopted to evaluate the effect. Results All incisions healed by first intention. All the patients were followed up 12-36 months (17 months on average). During the first 3 months after operation, sunken skin in the puncture point medial to the patella was observed in 12 knees; 10 knees suffered pain of the soft tissue lateral to the patella; 15 knees felt tense in the soft tissue medial to the patella, however, all these problems disappeared or recovered gradually after rehabil itation and conservative treatment. No recurrence of dislocation was observed during the follow-up. Lysholm score was significantly improved from preoperative 67.3 ± 5.7 to postoperative 96.6 ± 4.5 (t=3.241, P=0.003) and VAS score from 6.5 ± 0.5 to 1.8 ± 0.4 (t=2.154, P=0.040). According to Insall scale, the results were excellent in 18 knees, good in 5 knees, and fair in 2 knees at 1 year after operation with an excellent and good rate of 92%. Conclusion The improving procedure of arthroscopically assisted treatment for acute patellar dislocation is a minimally invasive operation and has a number of benefits. Its short-term cl inical outcome was satisfactory.
Objective To investigate the effectiveness of transosseous suture in medial patellofemoral ligament (MPFL) double bundle reconstruction. Methods The clinical data of 75 patients with recurrent patella dislocation who met the selection criteria between January 2014 and December 2017 were retrospectively analyzed. All of them were treated with MPFL double bundle reconstruction, and divided into study group (39 cases, using new transosseous suture technique) and control group (36 cases, using traditional suture anchor fixation) depending on the intraoperative fixation technique. There was no significant difference in gender, age, body mass index, affected knee side, preoperative tibial tuberosity-trochlear groove distance, Insall-Salvati ratio, knee range of motion, Kujala score, International Knee Documentation Committee (IKDC) score, congruence angle, and tilt angle between the two groups (P>0.05). The operation time, intraoperative blood loss, hospital stay, and postoperative complications were recorded and compared between the two groups. Kujala score, IKDC score, and knee range of motion were used to evaluate the functional improvement of patients before and after operation. The congruence angle and tilt angle were measured on X-ray films. Results There was no significant difference in operation time, intraoperative blood loss, and hospital stay between the two groups (P>0.05). Patients in both groups were followed up 24-36 months, with an average of 29.4 months. There was no complication such as incision infection, fat liquefaction, patellar redislocation, and prepatellar pain during follow-up. At last follow-up, the Kujala score, IKDC score, knee range of motion, congruence angle, and tilt angle of two groups significantly improved when compared with those before operation (P<0.05), while there was no significant difference between the two groups (P>0.05). ConclusionThe application of suture anchor or transosseous suture to complete MPFL double bundle reconstruction can restore patellar stability, and there is no significant difference in the short-term effectiveness between them.
Objective To investigate the effectiveness of modified single patellar tunnel medial patella femoral ligament (MPFL) reconstruction in the treatment of recurrent patellar dislocation. MethodsBetween January 2023 and June 2023, a total of 61 patients with recurrent patellar dislocation who underwent MPFL reconstruction with autologous semitendinosus were enrolled and divided into 2 groups using random number table method. In the patellar anchor group, 31 patients were treated with MPFL reconstruction with double medial patellar anchors, and 30 patients in the patellar tunnel group were treated with MPFL reconstruction with single patellar tunnel. The femoral ends of both groups were fixed with absorbable compression screws. There was no significant difference in baseline data such as gender, age, side, tibial tubercle-trochlear groove (TT-TG), Q angle, Caton-Deschamps index, number of dislocation, and preoperative Kujala score, preoperative patellar inclination angle (P>0.05). Patellar tunnel, patellar anchor position, patellar reduction, and the patellar inclination angle were measured by CT scan after operation. Kujala score was used to evaluate the function of knee joint before operation, at 2 weeks and 1, 3, 6, 12 months after operation. Incision aesthetic satisfaction score was performed at 3 months after operation. The signal-to-noise quotient (SNQ) of the transplanted tendon was measured by knee MRI at 12 months after operation to compare the maturity of the graft between the two groups. Results There was no significant difference in operation time and intraoperative blood loss between the two groups (P>0.05). Knee CT reexamination showed that the patellar tunnel and the patellar anchor position were consistent with the intraoperative fluoroscopy. There was no significant difference in the difference of the patellar inclination angle between the two groups before and after operation (P>0.05). All patients were followed up 12-14 months (mean, 12.8 months). There was 1 case of patellar anchor suture rejection in patellar anchor group, and the wound healed after debridement and dressing change. During the follow-up, there was no complication such as recurrence of patellar dislocation, infection and postoperative stiffness. The Kujala scores of the two groups significantly improved at each time point after 1 month of operation when compared with those before operation (P<0.05), and the Kujala scores of the two groups returned to normal levels at 3 months after operation. The Kujala score in the patellar tunnel group was significantly higher than that in the patellar anchor group in the very early stage (2 weeks) (P<0.05), and there was no significant difference between the two groups at other time points (P>0.05). Patients in the patellar tunnel group were significantly better than those in the patellar anchor group in the score of incision aesthetic satisfaction at 3 months after operation and the SNQ at 12 months after operation (P<0.05). Conclusion Modified single patellar tunnel MPFL reconstruction was used to treat patients with recurrent patellar dislocation without pathological TT-TG. The slide-fixation structure formed by single patellar tunnel positioning provides a variable degree of freedom for the reconstructed MPFL, which shows good effectiveness in the very early stage of the rehabilitation process.
Objective To investigate the effectiveness of reconstructing medial patellofemoral l igament with hamstring tendon autografts for the treatment of recurrent patellar dislocation under arthroscopy. Methods Between January 2005 and January 2010, 22 cases of recurrent patellar dislocation were treated by lateral retinacular release and reconstructionof the medial patellofemoral ligament with hamstring tendon autografts under arthroscopy. There were 5 males and 17 females, aged 15-19 years (mean, 17.3 years). The average number of dislocation was 4 (range, 3-8). The main cl inical symptoms were pain and swell ing of knee joint, weakness in the leg, and limited range of motion (ROM). The patellar tilt test, pressing pain of patellofemoral ligament insertion, and apprehension sign showed positive results. According to International Knee Documentation Committee (IKDC) scoring criteria, the subjective IKDC score was 36.7 ± 4.7, and the Lysholm score was 69.3 ± 3.8. X-ray films showed that the patella inclined outwards. Results All incisions healed by first intention. Twenty-two cases were followed up 18-49 months (mean, 34 months). Pain and swelling of knee joint and weakness were improved obviously. No recurrence was found during follow-up. The ROM of knee in flexion and extension was improved when compared with preoperative ROM. The subjective IKDC score was 92.4 ± 5.3 and the Lysholm knee score was 91.7 ± 5.2, showing significant differences when compared with preoperative scores (P lt; 0.05). Conclusion Reconstruction of the medial patellofemoral ligament with hamstring tendon autografts under arthroscopy is an effective method to treat recurrent patellar dislocation.
From 1974 to 1993, 20 patients with dislocation of patella in 26 knees were treated by surgical technique, including 11 males and 9 females, aged from 10 to 67,averaged 31 year old. Thirteen cases (16 knees) were available for followup with an average period of 6.4 years. Using the criteria of Insall, the result were excellent in 5 knees, good in 5 knees, fair in 3 knees and poor in 3 knees with a success rate of 62%. Based on the biomechanism of patella movement and the findings in this study, the mechanism of dislocation of patella and its biomechanical reconstruction principle as well as the factors influencing the operative results were discussed.
Objective To establish a three-dimensional finite element analysis model of the knee joint in fresh frozen cadavers, to verify the validity of the model and to simulate the stress distribution characteristics of the patellofemoral joint after combined proximal and distal knee extension rearrangement surgery for recurrent patellar dislocation. Methods One male and one female fresh frozen cadavers (4 knees in total), using voluntary body donations, were used to measure the maximum pressure on the patellofemoral articular surface at each passive flexion angle (0°, 30°, 60°, 90°, 120°) of the normal knee joint and the model after combined proximal and distal knee extension rearrangement surgery for recurrent patellar dislocation with tibial tuberosity-trochlear groove distance (TT-TG) value >2.00 cm using pressure-sensitive paper, respectively. Then, the 2 freshly frozen cadavers were used to construct three-dimensional finite element models of normal knee joints and postoperative knee joints, and the maximum pressure on the patellofemoral articular surface was measured at various passive flexion angles. The maximum pressure was compared with the measurement results of the pressure-sensitive paper to verify the validity of the three-dimensional finite element model. In addition, the maximum pressure on the patellofemoral joint surface measured by three-dimensional finite element was compared between the normal knee joint and the postoperative knee joint at various passive flexion angles, so as to obtain an effective three-dimensional finite element model for the simulation study of the stress distribution characteristics of the patellofemoral joint after combined proximal and distal knee extension rearrangement surgery for recurrent patellar dislocation. ResultsThe maximum pressure on the patellofemoral joint surface measured by pressure-sensitive paper and three-dimensional finite element measurements were similar at all passive flexion angles in the normal knee joint, with a difference of −0.08-0.06 MPa; the maximum pressure on the patellofemoral joint surface measured by pressure-sensitive paper and three-dimensional finite element measurements were also similar at all passive flexion angles in the knee after combined proximal and distal knee extension rearrangement surgery, with a difference of −0.04-0.09 MPa. The maximum pressure on the patellofemoral joint surface measured by three-dimensional finite elements were also similar between the normal knee joint and the knee joint after combined proximal and distal knee extension rearrangement surgery at all passive flexion angles, with a difference of −0.50-−0.03 MPa. ConclusionThe three-dimensional finite element model of the normal knee joint and the knee joint after combined proximal and distal knee extension rearrangement surgery can accurately and effectively quantify the change in the maximum pressure on the patellofemoral joint surface; for recurrent patellar dislocations with TT-TG value>2.00 cm, the combined proximal and distal knee extension rearrangement surgery can achieve a maximum pressure of the patellofemoral joint surface similar to that of the normal knee joint.