Objective of the study. To determine if the location and pattern of knee pain as described by the patients using the knee pain map was comparable with the intra articular pathology found on arthroscopy as well as to facilitate diagnosis based on pain. Methods. There were Sixty consecutive patients with acute and chronic knee pain participating in the study and they subsequently underwent arthroscopy of the knee joint as therapeutic or diagnostic procedure in day surgery. Those patients with extra articular pathologies, referred pain hip, back and foot were excluded from the study. All the participants were consented for the study; subjective data was recorded on the standardised knee pain map that included visual analogue pain scale preoperatively on the day of admission for arthroscopy. The findings of the arthroscopy including EUA were recorded on the on standard arthroscopy forms used in our department by the operating surgeon. Results. Patients on the knee pain map most often recorded sharp/stabbing pain (72%), followed by diffuse dull pain (14.5%), mixed dull and sharp pain (10 %) and burning pain (3.5%). 78 % of the localising pain pattern recorded on the knee pain map by the patients corresponded to the intra articular lesion found during knee arthroscopy. 18 % of the pain mapping location and pattern were not very specific to the intrarticular arthroscopic lesions and the rest were non specific. Conclusions. The majority of the patients could map the knee pain location and pattern correlating to the knee arthroscopic findings. The results from our study indicate that knee pain mapping can be used as a reliable tool to assist the clinician to determine the specific knee pain patterns correlating with discrete pathologic findings knee intra articular lesion

Surgical reconstruction of articular surfaces by transplantation of osteochondral autografts has shown considerable promise in the treatment of focal articular lesions. During mosaicplasty, each cylindrical osteochondral graft is centred over the recipient hole and delivered by impacting the articular surface. Impact loading of articular cartilage has been associated with structural damage, loss of the viability of chondrocytes and subsequent degeneration of the articular cartilage. We have examined the relationship between single-impact loading and chondrocyte death for the specific confined-compression boundary conditions of mosaicplasty and the effect of repetitive impact loading which occurs during implantation of the graft on the resulting viability of the chondrocytes. Fresh bovine and porcine femoral condyles were used in this experiment. The percentage of chondrocyte death was found to vary logarithmically with single-impact energy and was predicted more strongly by the mean force of the impact rather than by the number of impacts required during placement of the graft. The significance of these results in regard to the surgical technique and design features of instruments for osteochondral transplantation is discussed

INTRODUCTION. Loss of joint function is only exploited in osteoarthritis (OA) once severe impairment is apparent. Animal models allow for lesion induction and serial OA progression measures. We recently described an adjustable non-surgical loading model for generating focal cartilage lesions in only the lateral femur joint compartment, in which regimes can be adjusted so that these either do or do not progress spontaneously. Herein, we use ventral plane videographic treadmill gait analysis to determine whether gait changes can be used to discriminate between stable and spontaneously progressing lesions, induced by these two loading regimes. METHODS. Animals encountered normal conditions, except during loading (9N, 40 cycles, 0.1 Hz, 10 sec/ cycle) which was applied to right knees in two groups (n=8) of 8-week-old male CBA mice: i) loaded once; ii) loaded 3 times/week for 2 weeks. Gait (including: brake, propel, stance, stride, stride length, stride frequency, steps and paw area) was assessed 3 times/week for 2 weeks in each mouse using a DigigaitTM treadmill. Thereafter, mice received 5mg/kg carprofen for analgesia and gait analysis repeated on 3 further alternate days. RESULTS. The two loading regimes produced virtually identical gait modifications with delayed onset (apparent on day 3) which remained unchanged for 2 weeks; mice loaded once only showed modified contralateral limb use, but those loaded multiply exhibited additional ipsilateral front limb modifications; no changes in gait were observed in loaded limbs. Intriguingly, the two regimes produced distinct responses to analgesia. Load-induced gait changes were completely rescued by carprofen in mice loaded only once, whilst those in mice loaded repetitively persisted. CONCLUSION. Our findings reveal specific and reproducible, compensatory changes in contralateral, non-loaded limb gait induced by any joint loading which produces focal articular lesions, and modified ipsilateral front limb use only when progressing lesions are induced by repetitive loading. We find that pain relief completely alleviates all gait modifications associated with stable lesions induced by single loading, but not those induced by repetitive loading. Differing responses in mice with stable and progressive articular cartilage load-induced lesions suggests that gait behaviour in a mechanical loading model of OA may predict joint degeneration