Objective To investigate the cl inical therapeutic results of allograft tendon for anatomical reconstruction of medial patellofemoral l igament (MPFL) in patellar dislocations. Methods From September 2005 to June 2008, 20 patientswith patellar dislocation underwent MPFL reconstructions. There were 4 males and 16 females, aged 13 to 31 years (19 years on average). Patellar dislocations occurred in 7 left and 13 right knees, including 6 cases of acute dislocation and 14 cases of recurrent dislocation. The disease course was 1 day to 2 years. The frequency of dislocation was 1-6 (4 on average). Affected knee joint showed pain, swell ing and patellar instabil ity; the range of action for patella obviously increased. The X-ray films showed patellar dislocation or medial margin avulsion fracture. The preoperative Q angle was (15 ± 3)°, the congruence angle was (10 ± 11)°. Reconstruction was performed via allograft tendon. Allograft tendon was anchored to the superomedial pole of the patella by two bone anchors, and the other end was fixed at the natural MPFL insertion site near the medial femoral condyle with an interference screw in a bone tunnel. All patients were evaluated postoperatively; Kujala patellofemoral scores, objective knee function, compl ications, and reoperations were assessed. Results Primary heal ing was achieved in 18 cases and secondary heal ing in 2 cases. No infection or necrosis and absorption of grafts was observed. All patients were followed up for an average of 25.6 months (range, 6-34 months) postoperatively. At last follow-up, other patients had no pain, swell ing and patellar instabil ity except 1 case; neither patella redislocation nor fracture occurred. The X-ray films showed good position of anchors and tunnel 6 months after operation, and the congruence angle was (3 ± 8)°, showed statistically significant difference when compared with preoperation (P lt; 0.05). The postoperative Q angle was (15 ± 2)°, the Kujala knee function score improvedsignificantly from 60.8 ± 7.2 to 83.4 ± 8.0 at last follow-up, showing statistically significant difference (P lt; 0.05). According to Insall et al. for function, the results were excellent in 12 cases, good in 6 cases, and fair in 2 cases, the excellent and good rate was 90%. Conclusion MPFL reconstruction improves cl inical symptoms. Anatomical MPFL reconstruction is effective for patellar dislocation, and it offer good recovery of the pre-morbid patella mechanics. There would be l ittle bone loss when tendon is fixed by anchors, and there would be less patellar fracture than bone tunnel technique. The bone anchors also provide firm fixation. Allograft can avoid the graft harvest site morbidity, but it increases the cost of the surgery.
ObjectiveTo explore the treatment methed of recurrent patellar dislocation associated with old osteochondral fracture and to evaluate its effectiveness. MethodsBetween August 2010 and August 2014, 12 cases of recurrent patellar dislocation with old osteochondral fracture were treated. There were 4 males and 8 females with an average age of 18.3 years (range, 15-24 years). The left knee was involved in 7 cases and the right knee in 5 cases. All the patients had a history of patellar dislocation, the average interval from injury to first hospitalization was 7.6 months (range, 6-13 months). At preoperation, the range of motion (ROM) of the injured knee was (89.17±13.11)°; the Lysholm score was 56.67±18.91; the Q-angle was (17.50±5.28)°; and tibial tuberosity-trochlear groove (TT-TG) distance was (18.33±4.03) mm. The Q-angle was more than 20° and TT-TG distance was more than 20 mm in 6 of 12 cases. There were 6 cases of patellar osteochondral fracture, 5 cases of lateral femoral condylar osteochondral fracture, and 1 case of patellar osteochondral fracture combined with lateral femoral condylar osteochondral fracture. After osteochondral fracture fragments were removed under arthroscope, lateral patellar retinaculum releasing and medial patellar retinaculum reefing was performed in 2 cases, medial patellofemoral ligament (MPFL) reconstruction combined with both lateral patellar retinaculum releasing and medial patellar retinaculum reefing in 4 cases, and MPFL reconstruction, lateral patellar retinaculum releasing, medial patellar retinaculum reefing, and tibial tubercle transfer in 6 cases. ResultsAll wounds healed by first intention with no complication of infection, haematoma, skin necrosis, or bone nonunion. All patients were followed up 12-60 months with an average of 24.2 months. At 3 months after operation, all patellar dislocations were corrected; the Q-angle was (13.33±1.37)° and the TT-TG distance was (12.17±1.17) mm in 6 patients undergoing tibial tubercle transfer, showing significant differences when compared with preoperative values[(22.50±2.17)° and (21.33±2.34) mm] (t=15.25, P=0.00; t=8.27, P=0.00). All patients achieved relief of knee pain and knee locking; the knee ROM and the Lysholm score at last follow-up were (120.42±11.57)° and 89.25±9.71, showing significant differences when compared with preoperative ones (t=-11.61, P=0.00; t=-8.66, P=0.00). ConclusionIt has satisfactory short-term effectiveness to remove old osteochondral fragments that can not be reset and to correct patellar dislocation for recurrent patellar dislocation with old osteochondral fracture.
ObjectiveTo investigate the effectiveness of the arthroscopic lateral retinacular release combined with medial patellofemoral ligament (MPFL) reconstruction for patellar dislocation.MethodsBetween January 2016 and March 2017, 28 cases (32 knees) with patellar dislocation were treated by arthroscopic lateral retinacular release and MPFL reconstruction. There were 6 males (6 knees) and 22 females (26 knees) with an average age of 21 years (range, 17-29 years). The disease duration ranged from 2 days to 2 years (mean, 8 months). Apprehension test of all patients were positive. The preoperative Lysholm score was 68.34±12.26. Anteroposterior X-ray film showed the patellar subluxation or dislocation. The Q angle was (17.67±4.21)° and the distance of tibia tuberosity-trochlear groove was less than 20 mm. The femoral attachment of retinacular were fixed by the interference screws (16 knee) or the anchors (16 knee), respectively.ResultsAll incisions healed by first intention. All patients were followed up 6 months. The function of knee joint was significantly improved at 6 months after operation. The Lysholm score was 92.88±6.42 and the Q angle was (12.15±3.68)° at 6 months. There were significant differences in the Lysholm score and the Q angle between pre- and post-operation (t=–3.408, P=0.006; t=–2.317, P=0.004). Apprehension test of all patients were negative. No knee pain, knee weakness, and patellar dislocation occurred during follow-up. There was no significant difference in the Lysholm score and the Q Angle between the anchor group and interference screw group (t=–3.254, P=0.820; t=–3.576, P=0.940). ConclusionLateral retinacular release combined with MPFL reconstruction under arthroscopy can effectively improve the function of the knee joint for patients with Q angle less than 20° and TT-TG less than 20 mm, and the early effectiveness is good. There is no significant difference in knee function between the anchor and interference screw internal fixation.
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 review research progress on femoral attachment positioning during medial patellofemoral ligament (MPFL) reconstruction, so as to provide a reference for accurate positioning in clinic. Methods The literature at home and abroad on femoral attachment positioning during MPFL reconstruction was extensively reviewed and summarized. Results MPFL is the main ligament that restricts patellar outward migration, so MPFL reconstruction is the main treatment for patellar dislocation, but the accuracy of intraoperative femoral attachment positioning will significantly affect the surgical efficacy. At present, there are three main methods for femoral attachment positioning in MPFL reconstruction, including imaging positioning, bony landmark positioning, and new technology. Among them, the main imaging positioning method is the “Schöttle point” method, but it has high requirements for fluoroscopic positioning, and can only be accurately positioned under standard lateral fluoroscopy of the femur. The bony landmark positioning method mainly locates the femoral attachment by touching or dissecting the bony landmarks such as adductor tubercles and medial epicondyle of femur, but its disadvantages are that the positioning is not accurate enough, the intraoperative visual field exposure requirements are high, and a large incision is required. In order to avoid the problem that the simple bony landmark positioning method, in recent years, the combination of bony landmarks combined with arthroscopy, three-dimensional (3D) printing technology, and robot-assisted positioning methods have begun to be used in clinical practice. New technology localization methods have shown good results by preparing guides before operation, planning positioning paths in advance, or directly using robots to assist positioning during operation. Conclusion The accurate positioning of the femoral attachment in MPFL reconstruction is crucial, and the method of accurate and rapid intraoperative determination needs to be further improved and optimized. In the future, it is expected that the combination of computer image recognition correction technology and intraoperative position assistance will solve this problem.