Minimally invasive total knee replacement (MIS-TKR) has been reported to have better early recovery than conventional TKR. Quadriceps-sparing (QS) TKR is the least invasive MIS procedure, but it is technically demanding with higher reported rates of complications and outliers. This study was designed to compare the early clinical and radiological outcomes of TKR performed by an experienced surgeon using the QS approach with or without navigational assistance (NA), or using a mini-medial parapatellar (MP) approach. In all, 100 patients completed a minimum two-year follow-up: 30 in the NA-QS group, 35 in the QS group, and 35 in the MP group. There were no significant differences in clinical outcome in terms of ability to perform a straight-leg raise at 24 hours (p = 0.700), knee score (p = 0.952), functional score (p = 0.229) and range of movement (p = 0.732) among the groups. The number of outliers for all three radiological parameters of mechanical axis, frontal femoral component alignment and frontal tibial component alignment was significantly lower in the NA-QS group than in the QS group (p = 0.008), but no outlier was found in the MP group. . In conclusion, even after the surgeon completed a substantial number of cases before the commencement of this study, the supplementary intra-operative use of computer-assisted navigation with QS-TKR still gave inferior radiological results and longer operating time, with a similar outcome at two years when compared with a MP approach. Cite this article: Bone Joint J 2013;95-B:906–10

1. The characteristics of the regenerated knee meniscus are reviewed. 2. A case is reported in which a meniscus twice regenerated and was twice torn

Aims

The aim of this to study was to compare the previously unreported long-term survival outcome of the Oxford medial unicompartmental knee arthroplasty (UKA) performed by trainee surgeons and consultants.

Three women with osteoarthritis of the knee presented after sudden worsening of their symptoms. In each case this was found to be due to a stress fracture of the tibia. With treatment by rest and reduced activity, the fracture healed uneventfully in all three patients

We analysed data from the Oxford hip and knee questionnaires collected by the New Zealand Joint Registry at six months and five years after joint replacement, to determine if there was any relationship between the scores and the risk of early revision. Logistic regression of the six-month scores indicated that for every one-unit decrease in the Oxford score, the risk of revision within two years increased by 9.7% for total hip replacement (THR), 9.9% for total knee replacement (TKR) and 12.0% for unicompartmental knee replacement (UKR). Our findings showed that 70% of the revisions within two years for TKR and 67% for THR and UKR would have been captured by monitoring the lowest 22%, 28% and 28%, respectively, of the Oxford scores. When analysed using the Kalairajah classification a score of < 27 (poor) was associated with a risk of revision within two years of 7.6% for THR, 7.0% for TKR and 24.3% for UKR, compared with risks of 0.7%, 0.7% and 1.8%, respectively, for scores > 34 (good or excellent). Our study confirms that the Oxford hip and knee scores at six months are useful predictors of early revision after THR and TKR and we recommend their use for the monitoring of the outcome and potential failure in these patients

The relationship between meniscal tearing and degenerative joint disease was studied by macroscopic examination of 115 knees at necropsy. The incidence of meniscal pathology was 57 per cent. There was no overall difference in the severity and distribution of tibiofemoral degeneration, whether the meniscus was torn or normal. We found little evidence that degenerative meniscal tears cause osteoarthritis or vice versa

We studied 55 patients with stage-IIB osteosarcoma around the knee with respect to the expression of matrix metalloproteinase (MMP)-9 in the surviving tumour cells in surgical resection specimens. They were followed up for a minimum of 2.5 years. Factors significantly associated with poor overall survival were a high serum level of alkaline phosphatase at diagnosis and tumour cells expressing MMP-9 in the resection specimens. The only factor strongly associated with disease-free survival was the immunohistochemical status of tumour cells for MMP-9 in the resection specimens. The percentage of necrosis after chemotherapy failed marginally to reach statistical significance. On Cox regression analysis only MMP-9 remained significant for overall and disease-free survival

Joint débridement, by excision of synovial membrane, osteophytes, degenerate cartilage, loose bodies, and frequently the patella, has relieved the symptoms of osteoarthritis of the knee joint twenty-three times in a series of thirty-five operations reviewed after periods of one to nine years. The operation is considered a useful measure when symptoms resist conservative treatment

Twenty-two knees with osteochondritis dissecans diagnosed before skeletal maturity were followed prospectively into middle age: 32% had radiographic evidence of moderate or severe osteoarthritis at an average follow-up of 33.6 years; only half had a good or excellent functional result. We found that osteoarthritis was more likely to occur if the defect was large or affected the lateral femoral condyle

Ferrography is a technique for analysing wear by means of the magnetic separation of wear particles. To evaluate its application in human joints, the results of the ferrographic analysis of saline washings of symptomatic human knees were compared with the results of the arthroscopic examination of the same knees. Ferrography was found to be an extremely sensitive monitor of articular erosion, with a resolution far greater than that of arthroscopy. This was particularly apparent with knees suffering from a torn anterior cruciate ligament: arthroscopy detected no damage to the cartilaginous surfaces whereas ferrography detected a substantial level of "microdamage". The spectrum of wear particles showed qualitative and quantitative alterations depending upon the condition of the knee. Ferrography thus holds much promise as a potential differential diagnostic technique of great sensitivity, with particular relevance to the very early changes which precede clinical symptoms. Study of wear particles is also justified by evidence indicating an active role in the pathophysiological progression of arthritis

1. The results are presented of upper tibial osteotomy carried out in ten patients for osteoarthritis of the knee associated with lateral deformity. 2. The operation is indicated when there is severe pain, valgus or varus deformity, and a range of flexion of at least 90 degrees. 3. In every case pain has been relieved, and recovery of movement after operation has been easy

We evaluated the outcome of partial lateral meniscectomy of 31 knees in 29 patients whose knees were otherwise normal. The mean follow-up was 10.3 years. According to the Lysholm score, 14 knees were rated as excellent, four as good, five as fair and eight as poor, with a mean score of 80.5 points. Radiologically, only one lateral compartment was classified as grade 0, eight as grade 1, nine as grade 2, 11 as grade 3, and two as grade 4 according to Tapper and Hoover. No significant (p < 0.05) correlation was found between the amount of tissue resected and the subjective, clinical and radiological outcome. Although early results of lateral meniscectomy may be satisfactory, we have demonstrated that in the long term there was a high incidence of degenerative changes, a high rate of reoperation (29%) and a relatively low functional outcome score

We treated 15 patients by arthrodesis of the knee after removal of an infected total knee arthroplasty, using an Ilizarov ring fixator. Eight had a failed arthrodesis by another technique. The mean age of the patients was 75 years, the mean duration of retention of the frame was 28 weeks, the mean treatment time 51 weeks, and the mean follow-up 52 months. All but one knee fused at the first attempt, a rate of union of 93%. The incidence of complications related to treatment was 80%. The length of treatment and rates of complication were attributed to advanced age and the adverse local clinical factors in these patients. The Ilizarov method is a promising technique for achieving arthrodesis under these circumstances

1. Five elderly patients who suffered acute synovitis of one or both knee joints are reported. 2. All showed radiological evidence in several joints of cartilage calcification. 3. It is suggested that the synovitis in each case was due to calcium irritation of the synovial membrane. 4. In three of the patients it is shown that the synovial fluid calcium content was raised during the acute attack. 5. In all patients acute symptoms were relieved by aspiration of the effusion

1. Three cases are described of a calf swelling occurring in rheumatoid arthritis. 2. This condition has been described by Baker, though many of his patients had tuberculous infection of the knee. 3. The diagnosis may present difficulty because of the distance of the swelling from its origin in the knee joint. 4. Excision of the cyst is advised when it causes pain, but recurrence is likely if disease of the joint remains active

An anteroposterior radiograph of the leg to include the hip and ankle, taken with the patient standing, provides an estimate of the line of load-bearing at the knee. Gait analysis may be used to determine the way in which the load in the knee is shared between the medial and lateral compartments during normal walking. A comparison of the results from the two methods, carried out on a group of 47 patients, led to the conclusion that both calculations are required for the successful outcome of a tibial osteotomy or a total arthroplasty

We reviewed the relationship between the pattern of damage to the posterolateral corner of the knee and the position of the common peroneal nerve in 54 consecutive patients with posterolateral corner disruption requiring surgery. We found that 16 of the 18 patients with biceps avulsions or avulsion-fracture of the fibular head had a displaced common peroneal nerve. The nerve was pulled anteriorly with the biceps tendon. None of the 34 proximal injuries resulted in an abnormal nerve position. Whenever bone or soft-tissue avulsion from the fibular head is suspected, the surgeon should expect an abnormal position of the common peroneal nerve and appreciate the increased risk of iatrogenic damage

The morphological changes in bone and articular cartilage destruction have been described in sixteen consecutive cases of rheumatoid arthritis in which biopsy material was obtained during synovectomy of the knee. The following observations were made. 1. Bone and cartilage is replaced by fibrous granulation tissue which proliferates from periosteal and perichondrial fibroblasts. 2. These proliferative changes are distinct from the chronic synovitis of rheumatoid disease, but a chronic synovitis is necessary for them to appear. 3. Synovectomy does not remove the cells replacing bone and cartilage but its performance in some ways leads to their regression

We reviewed a single-surgeon series of 300 athletic patients who had undergone reconstruction of the anterior cruciate ligament in order to establish the relationship between the timing of the reconstruction and the incidence of meniscal and chondral pathology. The patients were divided into five groups according to the time from their injury to surgery as follows: less than two months, two to six months, six to 12 months, 12 to 18 months and more than 18 months. The presence of meniscal tears was recorded and chondral pathology was scored according to the system of the French Society of Arthroscopy. There was a significantly higher chance of a medial meniscal tear occurring in patients undergoing reconstruction after one year from their injury (odds ratio (7.99, p = 0.004). The odds of having a lateral meniscal tear did not change significantly with an increasing interval to reconstruction. The chance of patients developing degenerative changes was found to be significantly higher in the groups operated on after six months from injury (odds ratio 4.04, p = 0.005). We advocate that patients with deficiency of the anterior cruciate ligament should be counselled that there is a significant relationship between the duration of the instability of their knee and the subsequent incidence of both chondral changes and meniscal tears. In order to minimise these risks, we recommend that reconstruction be performed within the first year from injury