Ulstein 2014.
| Methods | Randomised controlled trial: participants were randomised utilising the block procedure, and allotments were kept in sealed, opaque envelopes. There were no blinded follow‐up assessments of primary outcomes. Participants were followed for median 9.8 years (range 4.9 to 11.4). Trial location: 3 different hospitals in Norway: Martina Hansens Hospital, Bærum; Oslo University Hospital, Oslo; Akershus University Hospital, University of Oslo. Recruitment: November 2000 to June 2006. |
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| Participants | Participants: 25 adults with chondral lesion in the knee were randomised to undergo either mosaicplasty (14 participants) or microfracture (11 participants); all were followed‐up. Included participants: Adults with isolated cartilage lesions ICRS grade 3 or 4, adults with symptomatic lesions due to osteochondral defect (osteochondritis dissecans), or lesions located on the femoral condyle or trochlea, with an area between 2 cm² and 6 cm² and depth < 10 mm. Participants had to be 18 to 50 years of age with Lysholm score < 80 and Tegner score < 6. Excluded participants: Patients with radiographic osteoarthritis, major misalignment, major ligament injury or instability, extension deficit > 3 degrees, flexion deficit > 5 degrees and chondral lesions of ICRS grade 3 or 4 on the tibial plateau or patella. Patients had contralateral impaired knee function that could have influenced their ability to follow the rehabilitation protocol. Age: OAT group mean (SD): 32.7 years (7.8) MF group mean (SD): 31.7 years (8.0) Gender: OAT group (number of men/women): 8/6 MF group (number of men/women): 6/5 Lesion size: OAT group median area (range): 3.0 cm² (2.0 cm² to 6.0 cm²) MF group median area (range): 2.6 cm² (2.0 cm² to 5.2 cm²) Sports activity (Tegner activity level score pre‐op): OAT group median (range): 2.5 (0 to 4) MF group median (range): 3 (0 to 4) Duration of symptoms: OAT group mean (SD): 75.8 (73.5) months MF group mean (SD): 111.0 (75.8) months |
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| Interventions | This study included OAT/mosaicplasty performed through a medial parapatellar arthrotomy or a mini‐invasive arthrotomy. Microfracture was performed all‐arthroscopically. Mosaicplasty or osteochondral autograft transplantation: Standard procedure described in the literature with press‐fit fixation (Acufex: Smith&Nephew). Mosaicplasty was performed through a medial parapatellar arthrotomy or a mini‐invasive arthrotomy, depending on the lesion size and localization. Debridement was done similar to that described for MF. The OAT mosaicplasty procedure was performed by obtaining small cylindrical osteochondral grafts (3.5 mm, 4.5 mm, or 6.6 mm in diameter) from the minimal weight‐bearing periphery of the femoral condyles and transplanting them ‘‘press‐fit’’ to recipient tunnels in the prepared lesion site. At the end of the procedure, the knee was moved through a full range of motion to check the stability of the osteochondral plugs. Microfracture: The procedure was arthroscopic and followed the standard procedures. Debridement of all damaged and unstable cartilage was performed, so as to obtain stable and healthy cartilage edges. An arthroscopic awl (Linvatec) was then used to perform multiple holes (‘‘microfractures’’) about 3 mm to 4 mm apart. The depth of the holes was considered appropriate when ‘‘fat‐pearls’’ emerged from the subchondral bone. Co‐interventions: The same rehabilitation program for both groups. All participants were hospitalised for a minimum of 5 days. Continuous passive motion (Kinetec®) 3–4 H 2x/day began on the first post‐operative day and continued for four days. Cold therapy and compression (Aircast Knee Cryo/Cuff®) were applied the two first days post‐operation. A maximum load of 15 kg to 20 kg weight bearing was allowed the initial 6 weeks post‐operation, gradually discontinuing the use of crutches up to 8 weeks. From 8 weeks, progression to full weight bearing was encouraged. Physiotherapist‐guided rehabilitation was initiated immediately post‐operation and was continued for a minimum of 6 months. Participants were generally allowed return to full activity after 6 months. However, participation in competitive contact sports or other activities that could expose the knee to pivoting forces was discouraged until 12 months post‐operation. |
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| Outcomes | Primary outcomes: Lysholm Score KOOS Failure: revision surgery (reoperation: ACI, OAT, proximal tibia osteotomy, loose body, debridement, and knee replacement) Complication: No complication mentioned Secondary outcomes: Activity level: Tegner activity scale Quality of cartilage: Radiographic arthrosis evaluation with Kellgreen and Lawrence criteria. |
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| Notes | The study was underpowered for the main outcome. Grant research support from Akershus University Hospital and the Foundation of Sophies Minde. The contact author provided additional information and data by e‐mail: this included the raw data from which we extracted the KOOS Quality of life, KOOS Pain, and Tegner results, the recently published article, and other methodological information on blinding. Author's information: "We did not perform blinding of the patients or the personnel due to the fact that «microfracture» was performed arthroscopically vs the mini open OAT «mosaicplasty». The skin wound/scar would be different in the two groups." "When it comes to the outcomes, the personnel (physiotherapists and orthopedic surgeons) were blinded when rating the Kellgeren‐Lawrence score in anonym[ised] radiographs, and when performing the dynamometer strength tests." |
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| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Low risk | A block randomisation was performed with a block size of 10 participants. |
| Allocation concealment (selection bias) | Low risk | Used sequentially‐numbered, opaque, and sealed envelopes. |
| Blinding of participants and personnel (performance bias) All outcomes | Unclear risk | There was no blinding of participant and personnel. |
| Blinding of outcome assessment (detection bias) All outcomes | High risk | There was no blinding of primary outcomes. |
| Incomplete outcome data (attrition bias) All outcomes | Low risk | No participants were lost to follow‐up. |
| Selective reporting (reporting bias) | Unclear risk | No protocol was available for comparison. |
| Other bias | Low risk | The study received grant support from Akershus University Hospital and the Foundation of Sophies Minde. This foundation is a non‐profit institution and the study is not biased by this grant. |
ACI: autologous chondrocyte implantation HSS: Hospital for Special Surgery ICRS: International Cartilage Repair Society IKDC: International Knee Documentation Committee KOOS: Knee Injury and Osteoarthritis Outcome Score OAT: osteochondral autograft transfer, i.e. mosaicplasty OCD: osteochondral defect MF: microfracture SD: standard deviation