Return to work following knee arthroplasty.

A retrospective study of a consecutive cohort of 109 patients, under the age of 60, who had either a Patellofemoral replacement (PFR), Unicompartmental replacement (UKR) or a Total knee replacement (TKR). They were operated on by two senior surgeons between 2002 and 2006 at the Avon Orthopaedic Centre in Bristol. The aim of this study was to look at the effect of knee replacement on the employment status of this group of patients. Data were collected from patient's hospital records and a questionnaire regarding occupational status was sent postoperatively to the patients. Statistical analysis showed that our groups were similar which meant that further comparison between them was valid. Eighty-two percent of the patients who were working prior to surgery and who had either a TKR or UKR were able to return to work postoperatively. Only 54% of those who had a PFR were able to return to work and this was statistically significant when compared with patients in the other two groups p=0.047. The median time for return to work postoperatively for the study population was 12 weeks. Those in the PFR group took significantly longer to do so (20 weeks) compared to those who had either a UKR (11 weeks) or TKR (12 weeks) p=0.01. Patient's subjective opinion as to their ability to work following knee arthroplasty was worse in the PFR group p=0.049. This is the first study to compare employment status following Patellofemoral, Unicompartmental knee and Total Knee Replacement. TKR and UKR are effective in returning patients under 60 years old to active employment and this is typically 3 months following surgery. Patients who had a PFR did not experience the same benefits in terms of numbers returning to work, time to do so and their subjective opinion as to their ability to cope with normal duties.

The progression of arthritis following lateral unicompartmental knee replacement.

In order to aid patient selection we have analysed the radiological progression of arthritis in the retained compartments following lateral unicompartmental knee replacement (UKR). Patients undergoing lateral UKR (St Georg Sled, Waldemar Link) between 1988 and 1999 were assessed. Radiographs taken post-operatively within 8 weeks and at 5 years were assessed. OA was classified using both the Altman and Ahlbach scoring systems. Identifying information on each radiograph was obscured so that the observer was blinded. Each radiograph was reviewed twice to assess intra-observer variability. Patients were assessed clinically using the Bristol Knee Score (BKS) at 1 and 5 years post-operation. Reproducibility for the Ahlbach systems was shown to be very good (kappa = 0.86) and the Altman moderate (kappa = 0.41). Thirty-two lateral UKRs were assessed at 5 years. Six out of 32 of the knees assessed showed definite progression of OA on the Ahlbäch score in the retained medial compartment and 11 out of 32 on the Altman. There was a statistically significant increase in the grade of OA, as assessed by both systems, at 5 years as compared to the post-operative radiograph (p < 0.001). The definite progression group had a mean BKS 10 points lower at 5 years. Six patients required revision to TKR for progression of arthritis in the retained compartments. Lateral compartment UKR can be a very successful procedure, but there is a greater rate of progression of arthritis in the retained medial compartment than following medial UKR.

Arthritis progression after patellofemoral joint replacement.

Progressive symptomatic tibiofemoral osteoarthritis (OA) following patellofemoral joint replacement (PFJR) may necessitate revision to total knee arthroplasty. This study was designed to quantify this problem in a prospective series of 103 consecutive patients who underwent PFJRs undertaken at our institution. At a mean follow-up of 7.1 years (66-102 months), 14 knees (14%) have been revised, 12 of those (12%) because of the development of symptomatic tibiofemoral OA, with a mean time to revision of 55 months (range 14 to 95 months). Available radiographs of the 89 unrevised knees were subject to blinded and randomised assessment by two observers. Postoperative AP knee radiographs were scored to assess for tibiofemoral OA progression, with definite progression seen in a median of 7% of medial compartments but 0% of lateral compartments, over a mean period of 51 months. Sulcus angles on preoperative 30 degrees skyline radiographs were measured to assess for trochlear dysplasia. Seventeen percent of the knees without preoperative trochlear dysplasia have been revised for progression of tibiofemoral OA, compared to none of the knees with preoperative trochlear dysplasia. Furthermore, in the unrevised knees, statistically significantly more radiographic progression of tibiofemoral OA was seen in those without preoperative trochlear dysplasia (p = 0.01). Our results suggest that progressive tibiofemoral OA following PFJR is an important cause of failure, but it is seen significantly less frequently when the patellofemoral arthritis is secondary to dysplasia of the femoral trochlea, suggesting that these patients are the ideal candidates for PFJR.

Radiological changes ten years after St. Georg Sled unicompartmental knee replacement.

Failure of a unicompartmental knee replacement (UKR) may be caused by progressive osteoarthritis of the knee and/or failure of the prosthesis. We have examined the fate of the other compartments of the knee by radiological assessment 10 years after operation. A total of 50 UKRs were performed on 45 carefully selected patients between 1989 and 1992. Fifteen patients died, two patients were lost to follow-up and two knees were revised. Standard long-leg weight-bearing anteroposterior views of the knee and skyline views of the patellofemoral joint were taken pre-operatively and at 8 months and 10 years after operation. The radiographs of the remaining 30 knees were reviewed three times by blind and randomized assessment to measure the progression of osteoarthritis within the joints. Two knees showed evidence of progression of osteoarthritis within the patellofemoral joint and three knees showed some progression of the opposite tibiofemoral compartment--but only on one of the radiological grading systems used for assessment. It is concluded that progression of arthritis in the unreplaced compartments is not a significant problem after fixed bearing UKR.

Knee scores in a 'normal' elderly population.

Many scoring instruments are now available for assessment of outcome after knee replacement. We performed a community study to record the three most frequently used knee scores in the UK in a 'normal' elderly population with no history of knee, hip, spine or lower limb disorder. The Oxford Knee Score (OKS), Bristol Knee Score (BKS), and American Knee Society Score (AKSS) were recorded in 100 volunteers whose mean age was 72 years. Normalised median scores in this population were 97% (42-100), 96% (69-100) and 98% (46-100), respectively. Significant negative correlations were found to exist between knee score and increasing age (P<0.001) and presence of coexistent 'major' medical conditions (P<0.001). The 'function' component of each score was the aspect of the score most influenced by these demographic variables. Comparison of outcomes after knee replacement on the basis of knee scores should take account of demographic variables.

In vitro evaluation of the resistance to dislocation of a meniscal-bearing total knee prosthesis between 30 degrees and 90 degrees of knee flexion.

An increased incidence of dislocation is the most important potential disadvantage introduced by the use of meniscal-bearing prostheses. The aim of this in vitro study was to measure the resistance to dislocation of a meniscal-bearing total knee arthroplasty in various circumstances and to establish which anatomic structures contribute to bearing stability. The prosthesis was implanted into cadaver knee specimens mounted in a 6 df rig. Dislocation was provoked by applying anteriorly or posteriorly directed forces (20-100N) to the tibia in the plane of the tibial plateau. Dislocation was defined as any stable displacement of the bearing (relative to the tibia or the femur) that persisted after release of the load applied to provoke it. The specimens were tested in an arc of knee flexion between 30 degrees and 90 degrees, with and without simulated quadriceps loads, with and without abducting and adducting loads, and before and after division of the posterior cruciate ligament and the lateral retinaculum. In the presence of quadriceps load, dislocation could not be provoked. In the absence of quadriceps load, dislocation was not provoked by posteriorly directed force but sometimes was caused by anteriorly directed force. All but 1 of the dislocations were unicompartmental, the lateral compartment proving much less stable than the medial. The tendency toward dislocation increased from 30 degrees to 60 degrees and from 60 degrees to 90 degrees of knee flexion. Adducting moments applied to the knee caused lift-off of the lateral femoral condyle from the bearing and increased the tendency toward dislocation. Abducting moments had the opposite effect. Division of the posterior cruciate ligament had no significant effect. Division of the lateral retinaculum increased the tendency toward dislocation. A femoral component that can be implanted without lateral release is desirable.

Perceptions of outcomes after unicompartmental and total knee replacements.

An independent measurement of the quality of outcome of 31 consecutive Oxford medial unicompartmental knee replacements in 28 patients and 130 total knee replacements in 104 patients performed between 1993 and 1997 is reported. The indications for surgery were anteromedial osteoarthritis for unicompartmental replacement and more extensive osteoarthritis for total knee replacement. All patients were treated by one surgeon. As a validated outcome measure of knee function, the Oxford 12-item knee questionnaire showed identical outcome in both groups with a mean score of 36.5 (maximum possible, 48). Neither the pain nor the functional outcomes were significantly different, although patients receiving unicompartmental replacement were better able to descend stairs. Two patients needed revision surgery in the unicompartmental replacement group compared with only one patient in the total knee replacement group. The femoral component of two unicompartmental replacements showed radiologic signs of loosening. The tibial component of one total knee replacement appeared loose, but the patient had no symptoms. In comparison with total knee replacement, implantation of meniscal bearing unicompartmental replacement technically is demanding and unforgiving. However, revision of a failed Oxford unicompartmental replacement is easier than revision of a failed total knee replacement, and the authors recommend this device for younger patients in whom one could expect a total knee replacement to fail within their lifetime.

High tibial osteotomy using a dynamic axial external fixator.

High tibial osteotomy is an accepted treatment for unicompartmental osteoarthritis of the knee. Conventional osteotomy can be a demanding procedure with potential for complications. Opening wedge high tibial osteotomy using an external fixator is an alternative that may have advantages in comparison with classic methods. The aims of the current study were to determine if opening wedge osteotomy using hemicallotasis techniques is safer than, and the outcome comparable with that of, conventional techniques. Seventy-six high tibial osteotomies were performed in 65 patients for primary osteoarthritis. The mean age of the patients was 54.8 years (range, 36-70 years). The mean followup was 6 years. The only serious complication occurred in one patient, who had chronic osteomyelitis develop 2 years after surgery. There were no neurologic or vascular complications. The authors think this technique is safer than conventional techniques. Survivorship at 5 and 10 years was 89% and 63%, respectively. The mean knee score in osteotomies was 26.6 (maximum possible score, 48). The outcome is comparable with, or better than, that of other techniques for osteotomy. Subsequent knee replacement, in cases requiring conversion, was straightforward. The mean score in knees that had osteotomies that were converted to total knee replacements was 33.7.

Patellar tendon length following opening wedge high tibial osteotomy using an external fixator with particular reference to later total knee replacement.

The aim of this retrospective study was to examine a cohort of patients who had undergone high tibial osteotomy (HTO) using the method of opening wedge hemicallotasis, and who later required conversion to total knee replacement (TKR). The incidence of patella infra and any technical difficulties encountered during TKR operation were examined. A consecutive series of 76 valgus osteotomies in 65 patients were carried out by one surgeon using a dynamic axial fixator (DAF). Later conversion to TKR, required for the progression of symptoms, was carried out in nine knees (seven patients) at a mean time from the initial osteotomy of 7 years (1.5-11). All of those patients who underwent HTO and subsequently required conversion to TKR were followed up. The patellar height was assessed by one observer in all knees pre- and post-HTO using the Insall and Salvati and Blackburne and Peel ratios. Using these criteria, only one case of patella infra occurred. There were no added technical difficulties in performing TKR as a result of the previous osteotomy and clinical outcomes using the Oxford knee score were satisfactory (34 where 48 is maximum).

Orthopod or orthogod? A prospective questionnaire study of post-operative patients' impressions of orthopaedic surgeons.

A questionnaire that challenged various stereotypes within the medical profession that are attached to orthopaedic surgeons was distributed to two groups of post-operative trauma in-patients: those with osteoporotic fractures and a much younger and active group. The results are presented here in a format that allows the reader to draw his/her own conclusions as to how 'orthopods' are perceived by their patients.

Radiological changes five years after unicompartmental knee replacement.

Failure of a unicompartmental knee replacement (UKR) may be caused by progressive osteoarthritis of the knee and/or failure of the prosthesis. Limb alignment can influence both of these factors. We have examined the fate of the other compartments and measured changes in leg alignment after UKR. A total of 50 UKRs was carried out on 45 carefully selected patients between 1989 and 1992. At operation, deliberate attempts were made to avoid overcorrection of the deformity. Four patients died, one patient was lost to follow-up and two knees were revised before review which was at a minimum of five years. Standard long-leg weight-bearing anteroposterior views of the knee and skyline views of the patellofemoral joint were taken before and at eight months and five years after operation. The radiographs of the remaining 43 knees were reviewed twice by blind and randomised assessment to measure the progression of osteoarthritis within the joints. Overcorrection of the deformity in the coronal plane was avoided in all but two knees. Only one showed evidence of progression of osteoarthritis within the patellofemoral joint, and this was only identified in one of the four assessments. Deterioration in the state of the opposite tibiofemoral compartment was not seen. Varus deformity tended to recur. Recurrent varus of 2 degrees was observed between eight months and five years after operation. There was no correlation between the postoperative tibiofemoral angle and the extent of recurrent varus recorded at five years. Changes in alignment may be indicative of minor polyethylene wear or of subsidence of the tibial component. The incidence of progressive osteoarthritis within the knee was very low after UKR. Patients should be carefully selected and overcorrection of the deformity be avoided.

Does arthritis progress in the retained compartments after 'Oxford' medial unicompartmental arthroplasty? A clinical and radiological study with a minimum ten-year follow-up.

We determined the outcome of 56 'Oxford' unicompartmental replacements performed for anteromedial osteoarthritis of the knee between 1982 and 1987. Of these, 24 were in patients who had died without revision, one was lost to follow-up and two had been revised. Of the remaining 29 knees, 26 were examined clinically and radiologically, two were only examined clinically and one patient was contacted by telephone. The mean age of the patients was 80.3 years. At a mean follow-up of 11.4 years (10 to 14) the measurements of the knee score, range of movement and degree of deformity were not significantly different from those made one to two years after operation, except that the range of flexion had improved. Comparison of fluoroscopically-controlled radiographs at a similar interval of time showed no change in the appearance of the lateral compartments. The retained articular cartilage continued to function for ten or more years which suggests that anteromedial osteoarthritis may be considered as a focal disorder of the knee. This justifies continued efforts to develop methods of treatment which preserve intact joint structures.

The length of the patellar tendon after unicompartmental and total knee replacement.

Patella infera may occur after reconstruction of the anterior cruciate ligament (ACL), high tibial osteotomy and total knee replacement (TKR). Restriction of movement of the knee and pain may result. Our aim was to compare the incidence and to assess the effects of patella infera after TKR and unicompartmental knee replacement (UKR). We reviewed radiographs of the knees of 84 patients who had had either TKR or UKR as part of a randomised, controlled trial The length of the patellar tendon was measured on serial radiographs taken before, at eight months and at five years after operation. There was no significant change in the length of the patellar tendon after UKR, but a significant reduction was observed after TKR. Five years after the operation, the shortening of the tendon had increased to a mean of 3.5 mm. Of the knees with TKR reviewed at five years, 34% developed patella infera, defined as 10% or more of shortening, compared with 5% of those with UKR. Shortening was greatest in those knees which had required a lateral release; in this subgroup the mean shortening was 7.2 mm. Shortening correlated with restriction of movement and pain in the knee. Our study has shown that patella infera develops in most patients after TKR with lateral release, and in approximately 25% of patients after TKR without this additional procedure. Patella infera rarely occurs after UKR. It is associated with restriction of movement and pain in the knee. It may be an effect of the more extensive exposure required to perform TKR and may, in part, explain the better clinical results of UKR.

Day-case or short-stay admission for arthroscopic knee surgery: a randomised controlled trial.

The Royal Colleges, The Audit Commission, and politicians have encouraged day-case care for patients undergoing arthroscopic knee surgery. However, there remains both public and professional concern regarding the acceptability and safety of this form of management, although there are clear economic benefits. In a prospective randomised controlled trial, 50 patients underwent arthroscopic surgery as a day-case and 50 patients were admitted overnight. Outcome was assessed by postal questionnaire 4 weeks after discharge. A linear visual analogue scale was used to measure pain levels. The response rate was 93%. The diagnoses and types of arthroscopic surgery were similar in both groups. In total, 94% of day-cases and 91% of patients admitted overnight expressed overall satisfaction. Pain after discharge was similar in both groups. Day-case management was preferred by 90% of day-case patients and by 64% of those admitted overnight. Of patients in the day-case group, 12% had to be admitted overnight because of recovery problems, but 7% of patients randomised to overnight stay discharged themselves. One patient admitted overnight required readmission because of a wound haematoma. Patients who had received day-case management returned to work significantly faster than those who had been admitted. Modern anaesthetic techniques with special attention to anti-emesis and pain control have reduced postoperative morbidity to acceptable levels. Provided that patients are properly selected and well informed, day-case care is preferable for the majority of patients undergoing arthroscopic surgery of the knee.

Nerve injury after posterior and direct lateral approaches for hip replacement. A clinical and electrophysiological study.

Nerve injury is a rare complication of total hip replacement which may be related to the exposure used for the operation. The posterior approach is traditionally associated with injury to the sciatic nerve. We have compared the incidence of nerve injury after primary total hip replacement (THR) using either a posterior or a direct lateral approach. We studied 42 consecutive patients undergoing primary total hip replacement. The surgeons used a posterior (22 patients) or direct lateral (20 patients) approach in accordance with their normal practice. The obturator, femoral, posterior tibial and common peroneal nerves were assessed clinically and electrophysiologically by electromyography (EMG) and measurement of the velocity of nerve conduction before operation and at four weeks after. All patients were free from symptoms of nerve injury after operation but five lesions were identified in four patients by the electrophysiological studies; the obturator nerve was involved in two, the femoral in one, the common peroneal in one and the posterior tibial in one. All these injuries occurred using the lateral approach. Clinical assessment alone underestimates the incidence of nerve injury complicating THR. Our study does not confirm the association of nerve injury with the posterior approach which had been described previously.

Clothing in laminar-flow operating theatres.

Bacterial shedding, wound contamination and clinical-infection rates in clean wounds are influenced by operating-theatre dress. The aim of this study was to clarify the relative contribution of hats, masks and clothing to the control of wound contamination in both ultraclean (enclosed vertical laminar-flow) and conventional (plenum ventilated) airflow theatres. Personnel wore varying combinations of dress in both types of theatre. Colony forming units (cfus) were measured on settle plates at head and waist height, and in the air by a centrifugal air sampler. Bacterial counts in conventional theatres were consistently high and were not significantly influenced by theatre dress. There was a 22-fold increase in cfus on settle plates at waist height when neither hat nor mask were worn, a 15-fold increase when a hat but no mask was worn and a fourfold increase with a mask but no hat in vertical laminar airflow enclosures, although air sample counts remained low. When balloon-cotton clothing was worn, rather than cuffed polyester with microfilament barrier-fabric gowns, cfu counts rose by a factor of six. The bacterial inoculum in conventionally ventilated theatres, or in ultraclean theatres if hat or mask are omitted or balloon-cotton clothing worn, is theoretically sufficient to infect a prosthetic arthroplasty. Theatre-air sampling alone does not reflect local contamination when a surgeon stands over a wound in a vertical laminar-flow enclosure, and both hats and masks are an important part of dress in such environments.

Secure fixation of lumbar osteotomy. Surgical experience with 50 patients.

Despite intensive conservative treatment, severe kyphotic spinal deformities may develop in patients with ankylosing spondylitis. Lumbar osteotomy can restore a horizontal visual field in these patients. Of 50 patients undergoing corrective lumbar osteotomy, there were 44 men and 6 women. A transpedicular screw and cable system was used in 37 patients. Mean correction of deformity was 38.7 degrees. Mean loss of correction was 4.8 degrees, but was 15 degrees in those cases in which transpedicular fixation was not used. All patients were able to see straight ahead after the operation. There were 2 deaths and 1 permanent sacral root lesion. Fixation failure was seen in 2 of 37 patients in whom transpedicular implants were used and in 3 of 13 in whom alternative methods of internal fixation were used.

Who should see orthopaedic outpatients--physiotherapists or surgeons?

Orthopaedic outpatient waiting lists are long and the majority of referrals are for conditions that do not respond to surgical intervention. Many of these patients are best managed by physiotherapy, orthotics or steroid injections, which can be administered by an appropriately trained physiotherapist. The effectiveness of a physiotherapist with extended training in orthotics and steroid injection was compared with staff grade orthopaedic surgeons in the management of orthopaedic outpatients judged unlikely to require surgery from the general practitioner's referral letter. Some 221 patients with mechanical low back pain and foot and shoulder disorders were seen by a physiotherapist and 97 by staff grade surgeons over a 10-month period. Outcome was assessed by postal questionnaire or telephone contact 6-12 months following discharge. Outcome was satisfactory in 80 per cent of patients overall, 65 per cent of low back and 69 per cent of neck pain, 80 per cent of foot and 83 per cent of shoulder disorders. An appropriately trained physiotherapist is as effective as staff grade surgeons in managing orthopaedic outpatients unlikely to benefit from surgical intervention. This has implications both in reduction of outpatient waiting lists and hospital doctor hours of work.

Is there a clinical interaction between low molecular weight heparin and non-steroidal analgesics after total hip replacement?

The benefits of parenteral non-steroidal analgesic drugs and low molecular weight heparin anticoagulants have been shown before, but there is concern that the use of these agents in combination may potentiate haemorrhagic side-effects because of simultaneous inhibition of the clotting cascade and platelet mechanisms of haemostasis. In a prospective controlled trial, 60 patients undergoing total hip replacement were randomised into two groups. Those in one group received intramuscular ketorolac and those in the other group opioid analgesia. All patients received enoxaparin subcutaneously, once daily. There were 34 patients in the NSAID group and 26 in the opiate group. There were no significant differences between the two groups for intraoperative blood loss, postoperative drainage, transfusion requirements, bruising, wound oozing and leg swelling. From this study it would appear that there is a low risk of significant haemostatic potentiation associated with concurrent use of low molecular weight heparin and a modest dose of ketorolac tromethamine.

Unicompartmental arthroplasty and high tibial osteotomy for osteoarthrosis of the knee. A comparative study with a 12- to 17-year follow-up period.

Comparable groups of patients with osteoarthritic knees who had either a St. Georg sledge unicompartmental arthroplasty or an upper tibial osteotomy were reviewed in 1985, five to ten years after operation. The results of unicompartmental arthroplasty were better, but it was uncertain whether the superior results would endure. The same groups have been reassessed after 12 to 17 years. Only 21 osteotomies and 15 unicompartmental arthroplasties remain. Good results were found in eight knees (42%) of the arthroplasty group and seven knees (21%) of the osteotomy group. Overall, five knees from the original cohort of 42 unicompartmental arthroplasties have required revision compared with 17 knees from the group of 49 osteotomies. This comparative analysis demonstrates that the superior early results from unicompartmental arthroplasty are maintained after a prolonged follow-up period. This prosthesis can be recommended with confidence to the elderly patient with unicompartmental osteoarthrosis.