Fourteen studies (n=597 patients, 610 fractures) were included. All were observational studies; four were retrospective and 10 were prospective in design. Quality scores ranged from 2 to 14 out of a possible 15. Most studies reported how patients were selected for the study. All studies except one followed up more than 85% of the sample. Only three three studies adjusted for relevant confounding factors. Only one study reported a power calculation. No studies reported confidence intervals. Descriptions of the study population were generally poor.
Clinical outcomes: Knee range of motion was assessed in nine studies. Extension ranged from 10° hyperextension to -20° and flexion ranged from 60° to 150°. Functional outcomes were assessed using a range of outcome measures in five studies. Two reported Lysholm scores: one had a mean score of 90 and the other reported good or excellent scores in 68% of patients. One study reported a mean score of 88 for lower extremity measures; another reported a mean Short Form 36 physical component score of 40 and mental component score of 51 at 12 months. Two studies reported Hospital for Special Surgery scores: one with a mean of 83.3 at two years and the other with a mean of 88 for extra-articular and 74 for intra-articular fractures. The mean Knee Society Score was 91 for extra-articular and 80 for intra-articular fractures in one study. One study reported 44 cases of excellent or good and one poor Rasmussen score. Four studies assessed time to full weight bearing and this ranged from six to 21 weeks.
Radiological outcomes: Two studies reported time to union, which ranged from six to 28 weeks. Two studies reported time to observable callus formation, which ranged from three to 10 weeks.
Postoperative complications: Postoperative loss of reduction was the most frequently reported complication. Other complications were valgus/varus deformity and inflexion and flexion/extension deformity. Cases of implant failure, proximal screw pull out, delayed union and non-union were reported. There were forty cases (7%) of superficial or deep infections. Cases of peroneal nerve injury and compartment syndrome were reported.