No long-term tunnel enlargement following anterior cruciate ligament reconstruction using autograft hamstring tendon with dual suspensory fixation.

PURPOSE: Bone tunnel widening following anterior cruciate ligament reconstruction (ACLR) is well documented, although the aetiology and clinical significance of this phenomenon remain unclear. At mid-term follow-up, a greater prevalence of tunnel enlargement has been reported with the use of hamstring (HS) grafts. However, there are paucity of data on what happens in the longer term. The aim of this study was to assess the change in femoral and tibial tunnel dimensions 15 years after four-strand HS ACLR. METHODS: This is a retrospective review of 15 patients who underwent arthroscopic ACLR using HS autograft tendon and were followed up radiographically at 4 months, 2 years and 15 years. Suspensory fixation was used for both ends of the graft. The diameters of the bone tunnels on posteroanterior (PA) and lateral radiographs were measured using digital callipers. Repeated measures analysis of variance (ANOVA) was used to examine change in tunnel width over time. RESULTS: Radiographic tunnel width did not significantly change between 4 months and 2 years. However, a significant decrease in width was found for both the femoral and tibial tunnels between the 2- and 15-year follow-up (P < 0.01): the femoral tunnel decreased by 50% and 51% in the PA and lateral views, respectively; the tibial tunnel decreased by 77% and 91% in the PA and lateral views respectively. There was no significant correlation between femoral or tibial tunnel width and flexion and extension deficits or with side to side differences in anterior tibial laxity at 15 years. CONCLUSIONS: This radiographic follow-up study of bone tunnel widening following HS ACLR with suspensory fixation demonstrated that tunnel width did not increase beyond 4 months and in fact had decreased significantly at long-term (15 years) follow-up. There was no correlation between tunnel width changes and clinical assessment of flexion and extension deficits or with side-to-side anterior knee laxity at 15-years. LEVEL OF EVIDENCE: IV.

Outcome of surgery for recurrent patellar dislocation based on the distance of the tibial tuberosity to the trochlear groove.

We evaluated the outcome in a series of patients with recurrent patellar dislocation who had either medial transfer of the tibial tuberosity and lateral release or an isolated lateral release as the primary treatment. The decision to use one or other procedure was based on a pre-operative distance between the tibial tuberosity to the trochlear groove (TTTG) of less than 10 mm to include the tibial tuberosity transfer in addition to the lateral release. Between April 2002 and December 2006, 49 patients (63 knees) underwent one of these procedures. A total of 35 patients (46 knees) was evaluated at a mean of 38 months (13 to 71) post-operatively. Medial transfer of the tibial tuberosity was performed in 33 knees and isolated lateral release in the remaining 13. Evaluation included the International Knee Documentation Committee (IKDC), the Kujala and the Short-form 36 scores. From the tibial tuberosity group 23 knees also underwent radiological examination at follow-up. There were further episodes of patellar dislocation in six of the 46 knees available for review. Further dislocation was noted in five of 33 knees (15.2%) in the tibial tuberosity transfer group and in one of 13 knees (7.7%) in the lateral release group. The mean subjective IKDC score was 80.4 (sd 11.6), the mean Kujala score 88 (sd 8.2) and the mean objective IKDC score was 79% normal and 21% nearly normal. The mean post-operative TTTG distance in the tibial tuberosity transfer group was 8.9 mm (3.2 to 15.7) compared with the mean pre-operative value of 16.8 mm (12.2 to 24.4).

Fragile X mental retardation protein replacement restores hippocampal synaptic function in a mouse model of fragile X syndrome.

Fragile X syndrome (FXS) is caused by a mutation that silences the fragile X mental retardation gene (FMR1), which encodes the fragile X mental retardation protein (FMRP). To determine whether FMRP replacement can rescue phenotypic deficits in a fmr1-knockout (KO) mouse model of FXS, we constructed an adeno-associated virus-based viral vector that expresses the major central nervous system (CNS) isoform of FMRP. Using this vector, we tested whether FMRP replacement could rescue the fmr1-KO phenotype of enhanced long-term depression (LTD), a form of synaptic plasticity that may be linked to cognitive impairments associated with FXS. Extracellular excitatory postsynaptic field potentials were recorded from CA3-CA1 synaptic contacts in hippocampal slices from wild-type (WT) and fmr1-KO mice in the presence of AP-5 and anisomycin. Paired-pulse low-frequency stimulation (PP-LFS)-induced LTD is enhanced in slices obtained from fmr1 KO compared with WT mice. Analyses of hippocampal synaptic function in fmr1-KO mice that received hippocampal injections of vector showed that the PP-LFS-induced LTD was restored to WT levels. These results indicate that expression of the major CNS isoform of FMRP alone is sufficient to rescue this phenotype and suggest that post-developmental protein replacement may have the potential to improve cognitive function in FXS.

A prospective longitudinal study to assess psychological changes following anterior cruciate ligament reconstruction surgery.

OBJECTIVE: To determine whether the psychological characteristics of athletes who have undergone an anterior cruciate ligament (ACL) reconstruction change during rehabilitation are related to returning to competitive sport. DESIGN: Prospective longitudinal study. METHOD: 87 athletes completed the Emotional Response of Athletes to Injury Questionnaire (ERAIQ) and the ACL Return to Sport after Injury scale (ACL-RSI) at 3, 6 and 12 months following ACL reconstruction surgery. Physical outcome measures were also taken at each time point. RESULTS: At 12 months 44 (51%) participants had returned to competitive sport and 43 (49%) participants had not returned. There were no differences in physical recovery or scores on the ERAIQ between the two groups. Participants who had returned to competitive sport at 12 months, however, scored significantly higher on the ACL-RSI scale (reflecting a more positive psychological response about sport participation) at both 6 and 12 months than participants who had not returned to competitive sport. CONCLUSIONS: During rehabilitation there are significant psychological differences regarding sport resumption between athletes who do, and do not, resume competitive sport 12 months following ACL reconstruction. These differences occur as early as 6 months postoperatively and highlight the importance of addressing all aspects of an athlete's recovery in order to help facilitate the athlete returning to sport.

Kinematic patterns associated with accuracy of the drop punt kick in Australian Football.

Research into the kinematics of movement associated with the accuracy of the drop punt kick in Australian Football has been limited. The aim of this study was to examine pelvic and lower limb kinematics during the performance of a drop punt kick, in order to identify factors associated with accurate kicking performance. Ten professional Australian Football League (AFL) players performed 20 drop punt kicks towards a target situated 15m away, using their preferred leg. A three-dimensional motion analysis system was used to record the kicking motion from heel contact of the support limb through to ball contact. The subjects were divided into an accurate group (> or =50% accuracy; n=5) and an inaccurate group (<50% accuracy; n=5) based on target hit rate. Kinematic profiles for both kicking and support limbs were compared between the two groups. Results showed that the accurate group had significantly greater hip flexion in both limbs and greater knee flexion in the support limb throughout the kicking movement. The accurate group also had significantly greater anterior pelvic tilt at heel contact (accurate 20.8 degrees ; inaccurate 12.7 degrees ). These data show that kinematic differences in lower limb joint angles may be related to kicking accuracy.

A systematic review of the effect of proprioceptive and balance exercises on people with an injured or reconstructed anterior cruciate ligament.

This systematic review investigated the effect of proprioceptive and balance exercise on outcomes following injury and surgical reconstruction of the anterior cruciate ligament (ACL). Five studies of high quality that offered empirical evidence by comparing one rehabilitation program to another were included in this review. There is some evidence that proprioceptive and balance exercise improves outcomes in individuals with ACL-deficient knees. Improvements in joint position sense, muscle strength, perceived knee joint function, and hop testing were reported following proprioceptive and balance exercise. Only one included study investigated proprioceptive exercise following ACL reconstruction. Benefits were noted in the proprioceptive group for measures of strength and proprioception; however, no benefits were noted for any measures of activity. No detrimental effects--such as increased passive joint laxity or decrease in strength--were noted when compared with standard rehabilitation programs for both ACL-deficient and ACL-reconstructed individuals. Further research is required to determine if proprioceptive and balance exercise improves long-term outcomes such as return to sport.

A randomised controlled trial of proprioceptive and balance training after surgical reconstruction of the anterior cruciate ligament.

A randomised controlled trial (29 participants) was used to compare a 6-week proprioceptive and balance exercise program with a 6-week strengthening program in the early phases of rehabilitation after anterior cruciate ligament (ACL) reconstruction. Measurements of functional activity were taken by a blinded assessor before the intervention and at the end of the 6 weeks. Results demonstrated that there were no significant differences between groups on hop testing at 6 weeks. For several items in the Cincinnati knee rating system and the patient specific functional scale however, the strengthening group improved more than the proprioceptive and balance group (p < .05). The hypothesis that proprioceptive and balance training would improve functional activity more than strengthening exercises was not supported. There was either no difference between the two forms of exercise or strength training may be more beneficial than proprioceptive and balance training in the early phase of rehabilitation after ACL reconstructive surgery.

Abnormal tenocyte morphology is more prevalent than collagen disruption in asymptomatic athletes' patellar tendons.

This study investigated the prevalence of each of the four features of patellar tendinosis in asymptomatic athletic subjects undergoing patellar tendon anterior cruciate ligament (ACL) reconstruction. Fifty subjects (39 males and 11 females) undergoing ACL reconstruction using a patellar tendon graft were screened for previous tendon symptoms, training and playing history and had their patellar tendons examined with ultrasound prior to surgery. During surgery, a small piece of proximal posterocentral tendon was harvested, fixed and examined under light microscopy. Histopathological changes were graded for severity. Results demonstrate that 18 tendons were abnormal on light microscopy and 32 were normal. There were no differences between subjects with and without pathology in respect of training, recovery after surgery and basic anthropometric measures. Three tendons were abnormal on ultrasound but only one had proximal and central changes. Tendons showed a consistent series of changes. Tenocyte changes were found in all but one of the abnormal tendons. In all but one of the tendons with increased ground substance there were tenocyte changes, and collagen separation was always associated with both tenocyte changes and increased ground substance. No tendons demonstrated neovascularization. It appears that cellular changes must be present if there is an increase in ground substance, or collagen and vascular changes. Further research is required to confirm these findings.

Effect of physiotherapy attendance on outcome after anterior cruciate ligament reconstruction: a pilot study.

BACKGROUND: In many centres patients are routinely referred for physiotherapy after anterior cruciate ligament (ACL) reconstruction. However, to date the role and amount of supervised physiotherapy required has not been clearly established. OBJECTIVE: To establish whether there was any difference in outcome between a group of patients who attended physiotherapy regularly after ACL reconstruction and a group who attended only infrequently. METHODS: Ten patients who had attended physiotherapy infrequently (mean 1.9 visits) during the first six months after ACL reconstructive surgery were matched for age, sex, graft type, and activity level and occupation before injury with 10 patients who had attended physiotherapy regularly (mean 26.5 visits). Outcome was assessed at 12 months using the Cincinnati knee rating system and the IKDC form. RESULTS: Compared with the regular physiotherapy group, patients in the minimal physiotherapy group had fewer symptoms (mean Cincinnati symptom score 46.2 v 43.4, p = 0.045). There was also a trend towards higher overall Cincinnati knee scores in the minimal physiotherapy group (mean 93.7 v 87.3, p = 0.06) but no difference in IKDC ratings. CONCLUSION: These preliminary results indicate that some patients who choose to attend physiotherapy on a very limited basis after ACL reconstruction can achieve satisfactory, if not better, outcomes than patients who attend physiotherapy regularly.

Early post-operative morbidity following anterior cruciate ligament reconstruction: patellar tendon versus hamstring graft.

This study documented postoperative morbidity during the first 4 months following anterior cruciate ligament (ACL) reconstruction using either patellar tendon or hamstring tendon autograft. Sixty-five patients undergoing primary arthroscopically assisted single-incision ACL reconstruction were randomized to have a central third bone patellar tendon bone autograft (PT) or a doubled semitendinosus/doubled gracilis autograft (HS). Postoperatively patients undertook a standard 'accelerated' rehabilitation protocol. Patients were reviewed after 2 weeks, 8 weeks, and 4 months. At each review the location and severity of general knee pain and the presence and severity of anterior knee pain (AKP) were recorded as were the presence and size of an effusion as well as the active and passive flexion and passive extension deficits compared to the contralateral limb. Pain on kneeling, KT-1000 measured side to side difference in anterior tibial displacement, isokinetic assessment of quadriceps and hamstring peak torque deficits, IKDC score and Cincinnati sports activity level were also recorded after 4 months. After 2 weeks more patients in the PT group complained of AKP and reported that the pain was more severe. After 8 weeks there was no significant difference between the groups for any variable. After 4 months the severity of general pain experienced and the incidence of pain on kneeling were greater in the PT group. The PT group also demonstrated a significantly greater quadriceps peak torque deficit at 240 degrees /s. IKDC scores were higher in the HS group, but Cincinnati sports activity scores were higher in the PT group. Although we observed a lower morbidity in the HS group, primarily related to pain, the severity of pain in both groups was relatively low and, in light of the higher mean sports activity level observed in the PT group at 4 months the clinical impact of the difference may not be significant.

Clinical value of magnetic resonance imaging of the knee.

BACKGROUND: Magnetic resonance (MR) imaging is an accurate imaging modality of the knee. The role of MR in clinical practice has not been precisely defined, largely due to the relative expense of the technique. METHODS: For each new patient with a knee problem who was referred for MR, a provisional diagnosis was made together with a level of certainty regarding the diagnosis. The waiting time for the scan was recorded. To assess clinical usefulness the MR diagnosis was compared with the provisional diagnosis and classified according to the following descending order of value: unexpected negative (no intra-articular pathology), confirmatory negative, unexpected positive or confirmatory positive. To assess accuracy of the MR diagnosis, the operative diagnosis was compared to the MR diagnosis in those patients who underwent arthroscopy. RESULTS: Fifty-two per cent of scans were assessed as being very useful and a further 20% were assessed as being moderately useful. Magnetic resonance had a 95% accuracy for medial meniscal tears, 91% accuracy for lateral meniscal tears, and 98% accuracy for anterior cruciate ligament tears, similar to previously reported studies. The diagnostic arthroscopy rate in the patients who underwent MR scanning was similar to that in patients for whom the surgeon was more confident about the diagnosis and who therefore did not undergo MR scanning. The diagnostic arthroscopy rate could have been reduced if surgery had not been performed in 14 patients who had a negative MR scan. CONCLUSIONS: There is a role for selective use of MR in the assessment of knee conditions. In particular, MR can be used to reduce the diagnostic arthroscopy rate.

Bone tunnel enlargement following anterior cruciate ligament reconstruction: a randomised comparison of hamstring and patellar tendon grafts with 2-year follow-up.

Radiographic tibial and femoral bone tunnel enlargement has been demonstrated following anterior cruciate ligament (ACL) reconstruction. This study investigated whether bone tunnel enlargement differs between four-strand hamstring (HS) and patellar tendon (PT) ACL reconstructions over the course of a 2-year follow-up. Patients undergoing primary ACL reconstruction (n = 65) were randomised to receive either a PT or HS autograft. Femoral fixation in both groups was by means of an Endobutton. On the tibial side the PT grafts were fixed using a metallic interference screw, and the HS tendons by sutures tied to a fixation post. The PT grafts were inserted such that the proximal end of the distal bone block was within 10 mm of the tibial articular surface, resulting in a portion of free patellar tendon in the femoral tunnel immediately proximal to the articular surface. Patients were reviewed after 4 months and 1 and 2 years. Tunnel enlargement was determined by measuring the widths of the femoral and tibial tunnels with a digital caliper in both lateral and anteroposterior radiographs. Because of the presence of the interference screw and the proximity of the bone block to the tibial articular surface, the tibial tunnel could not be reliably measured in the PT group. Measurements were corrected for magnification, and changes in tunnel width were recorded relative to the diameters drilled at surgery. Standard clinical measures were also noted. In 32% of patients in the PT group there was femoral tunnel obliteration from 4 months onwards. For the other patients there was a significantly greater increase in femoral tunnel width in the HS group than in the PT group at each follow-up, but no significant change with time. There was also a marked increase in tibial tunnel width in the HS group at 4 months but not thereafter. There was no relationship between tunnel enlargement and clinical measurements. Although tunnel enlargement is more common and greater with HS grafts, it does not appear to affect the clinical outcome in the first 2 postoperative years. Femoral suspensory fixation does not in itself appear to be the principal cause of femoral tunnel enlargement, at least for PT grafts.

Mutations in domain V of the Sendai virus L polymerase protein uncouple transcription and replication and differentially affect replication in vitro and in vivo.

The Sendai virus L and P proteins comprise the viral RNA-dependent RNA polymerase. The L subunit is thought to be responsible for all the catalytic activities necessary for viral RNA synthesis. Sequence alignment of the L proteins of negative-stranded RNA viruses revealed six regions of good conservation, domains I-VI, which are thought to correspond to functional domains of the protein. Domain V, amino acids 1129-1378, has no recognizable motifs, and to date its function is unknown. Site-directed mutagenesis was used to construct mutations across domain V. The mutant L proteins were all stably expressed and were tested for activity in several aspects of RNA synthesis. One set of mutants could synthesize more le+ RNA than mRNA, while two mutants showed the opposite phenotype, synthesizing more mRNA than le+ RNA. The majority of the mutants could synthesize mRNA, but not genome RNA in vitro, thus uncoupling transcription and replication. Several mutants could replicate in vivo, but not in vitro, at nearly wildtype L levels, suggesting the importance of the intact host cell for replication in some instances. One L mutant, SS24, was virtually inactive in all viral RNA synthesis. SS24 L was able to form a polymerase complex that recognized the nucleocapsid template, and thus these amino acids are essential for the initiation of RNA synthesis.

Comparison of identical temperature-sensitive mutations in the L polymerase proteins of sendai and parainfluenza3 viruses.

The L subunit of the RNA-dependent RNA polymerase of negative strand RNA viruses is believed to possess all the enzymatic activities necessary for viral transcription and replication. Mutations in the L proteins of human parainfluenza virus type 3 (PIV3) and vesicular stomatitis virus (VSV) have been shown to confer temperature sensitivity to the viruses; however, their specific defects have not been determined. Mutant PIV3 L proteins expressed from plasmids were tested for temperature sensitivity in transcription and replication in a minigenome reporter system in cells and for in vitro transcription from purified PIV3 template. The single L mutants, Y942H and L992F, were temperature sensitive (ts) in both assays, although viral RNA synthesis was not completely abolished at the nonpermissive temperature. Surprisingly, the T1558I L mutant was not ts, although its cognate virus was ts. Thus the ts defect in this virus may be due to the abrogation of an essential interaction of the mutant polymerase with a host cell component, which is not measured by the RNA synthesis assays. Most of the combinations of the PIV3 L mutations were not additive and did not show temperature sensitivity in in vitro transcription. Since they were ts in the minigenome assay in vivo, replication appears to be specifically defective. The ts mutations in PIV3 and VSV L proteins were also substituted into the Sendai L protein to compare the defects in related systems. Only Sendai Y942H L was ts in both transcription and replication. One Sendai L mutant, L992F, gave much better replication than transcription. Several other mutants could transcribe but not replicate in vitro, while replication in vivo was normal.

Mutations in conserved domains IV and VI of the large (L) subunit of the sendai virus RNA polymerase give a spectrum of defective RNA synthesis phenotypes.

The Sendai virus RNA polymerase is a complex of two virus-encoded proteins, the phosphoprotein (P) and the large (L) protein. When aligned with amino acid sequences of L proteins from other negative-sense RNA viruses, the Sendai L protein contains six regions of good conservation, designated domains I-VI, which have been postulated to be important for the various enzymatic activities of the polymerase. To directly address the roles of domains IV and VI, 14 site-directed mutations were constructed either by changing clustered charged amino acids to ala or by substituting selected Sendai L amino acids with the corresponding sequence from measles virus L. Each mutant L protein was tested for its ability to transcribe and replicate the Sendai genome. The series of mutations created a spectrum of phenotypes, from those with significant, near wild-type, activity to those being completely defective for all RNA synthesis. The inactive L proteins, however, were still able to bind P protein and form a polymerase capable of binding the nucleocapsid template. The remainder of the mutations reduced, but did not abolish, enzymatic activity and included one mutant with a specific defect in the synthesis of the leader RNA compared with mRNA, and three mutants that replicated genome RNA much more efficiently in vivo than in vitro. Together, these data suggest that even within a domain, the function of the Sendai L protein is likely to be very complex. In addition, SS3 and SS10 L in domain IV and SS13 L in domain VI were shown to be temperature-sensitive. Both SS3 and SS10 gave significant, although not wild-type, activity at 32 degrees C; however, each was completely inactivated for all RNA synthesis at 37 and 39.6 degrees C. SS13 was completely inactive only when synthesized at the higher temperature. Each polymerase synthesized at 32 degrees C could only be partially heat inactivated in vitro at 39.6 degrees C, suggesting that inactivation involves both thermal lability of the protein and temperature sensitivity for its synthesis.

Mutations in conserved domain II of the large (L) subunit of the Sendai virus RNA polymerase abolish RNA synthesis.

The large (L) protein of Sendai virus complexes with the phosphoprotein (P) to form the active RNA-dependent RNA polymerase. The L protein is believed to be responsible for all of the catalytic activities of the polymerase associated with transcription and replication. Sequence alignment of the L proteins of negative-strand RNA viruses has revealed six conserved domains (I-VI) thought to be responsible for the enzymatic activities. Charged-to-alanine mutagenesis was carried out in a highly charged, conserved region (amino acids 533-569) within domain II to test the hypothesis of Müller et al. [J. Gen. Virol. 75, 1345-1352 (1994)] that this region may contribute to the template binding domain of the viral RNA polymerase. The mutant proteins were tested for expression and stability, the ability to synthesize viral RNA in vitro and in vivo, and protein-protein interactions. Five of the seven mutants were completely defective in all viral RNA synthesis, whereas two mutants showed significant levels of both mRNA and leader RNA synthesis. One of the transcriptionally active mutants also gave genome replication in vitro although not in vivo. The other mutant was defective in all the replication assays and thus the mutation uncoupled transcription and replication. Because the completely inactive L mutants can bind to the P protein to form the polymerase complex and the polymerases bind to the viral nucleocapsid template, these amino acids are essential for the activity of the L protein.

Waiting times for appointments with orthopaedic surgeons in Victoria: 1995-97.

BACKGROUND: A number of different models have been proposed for determining surgical workforce requirements. METHODS: In 1995 the Workforce Subcommittee of the Victorian Regional Branch of the Australian Orthopaedic Association commenced a prospective evaluation of waiting times for both urgent and nonurgent appointments with orthopaedic surgeons in Victoria. RESULTS: The results for the 3 years, 1995-97, show no significant change in the waiting time for nonurgent appointments and no difference between metropolitan and rural areas. The waiting time for an urgent appointment increased from 1995 to 1997 for the state of Victoria and for metropolitan Melbourne but not for rural areas. However, the median waiting time for an urgent appointment did not change. CONCLUSION: Overall the waiting times were found to be satisfactory by previously reported standards.

Use of a discistronic vector for the quantitation of HCV IRES activity.

The 5'-untranslated region of hepatitis C virus (HCV) has been shown to function as an internal ribosomal entry site, or IRES. The biological function of the HCV IRES has been shown to be essential for initiation of translation of the viral proteins by host ribosomes. With this critical role in HCV replication, the IRES makes an attractive target for the development of antiviral compounds Furthermore, since eukaryotic translation is not initiated via an IRES, agents that specifically interfere with function of the HCV IRES may be relatively nontoxic to the host Fundamental to the testing of any of these antivirals is a system to evaluate their efficacy. This chapter describes the use of a dicistromc vector in an in vitro system to assess the translational initiation efficiency of isolated HCV IRES elements.

Construction of recombinant vaccinia virus expressing HCV genes.

Hepatitis C virus (HCV) remains the leading cause of non-A, non-B hepatitis, and a major indicator for orthotopic liver transplantation. To date, finding a cure or even a commonly effective therapy for infection with HCV has proven to be an elusive goal. One major problem that has hampered attempts to develop antiviral agents is the ongoing inability to grow the virus in tissue culture. Without an efficient in vitro system for the propagation of HCV, it is difficult to generate the large amounts of viral protein needed for this sort of study; nor can the effects of known antiviral agents be assessed on the replication of HCV. Recently, some laboratories have reported preliminary evidence of HCV replication in cultured cells (1,2), but even the best of these systems does not produce significant amounts of progeny virus. Although these methods may be applicable in the future, at present they are not yet practical.

Patellar resurfacing versus retention in total knee arthroplasty.

We studied 40 patients in whom the patella was not severely deformed and who were undergoing primary total knee arthroplasty (TKA) for osteoarthritis by one surgeon using one type of prosthesis. They were randomly allocated either to have the patella retained or resurfaced with a cemented, all-polyethylene component regardless of the state of the patellar articular cartilage. Apart from removal of osteophytes, no surgery was undertaken on the retained patellae. All 38 surviving patients were evaluated at three years using the HSS knee score and a new, specifically designed Patellar score (maximum score of 30). No TKA was revised, but two patients in the resurfacing group had a further unrelated procedure. The mean HSS and Patellar scores at follow-up were 89 and 28 in the patellar retention group and 83 and 26 in the patellar resurfacing group. Statistically significant lower scores for both were recorded in women and in heavier patients. Stair-climbing ability was significantly better in the retention group. Although there were no complications related to patellar resurfacing, in the medium term we did not find any significant benefit from resurfacing the patella during TKA for osteoarthritis if it was not severely deformed.