Gap balanced adjusted mechanical alignment versus measured resection mechanical alignment: a randomised controlled trial.

INTRODUCTION: Alignment goals in total knee replacement (TKR) is a topical subject. This study compares the short-term functional outcomes and patient reported outcome measures (PROMs) of two philosophies for knee arthroplasty alignment: measured resection (MR) and an individualised alignment philosophy, with the tibia mechanically aligned and an instrumented gap balancer (GB) to align the femur in both flexion and extension. PATIENTS AND METHODS: 94 knees were enrolled in this randomised controlled trial. The surgical protocol used a MR technique for mechanical alignment or a GB technique for individualised alignment. Primary outcome was quadriceps strength. Secondary outcomes included validated functional tests and PROMs as well as patient satisfaction. Outcomes were assessed pre-operatively, at 6 weeks, 3, 6 and 12 months post-operatively. RESULTS: At 12-month follow-up, there was no significant difference in the change from baseline mean quadriceps peak torque between the two groups (p = 0.988). Significant improvement in the change in range of motion (ROM) in the GB group compared to the MR group at 3 months (13° vs 6° p = 0.028) but this improvement was not significant at 1 year (20° vs 17° p = 0.21). The functional test of balance showed statistically significant improvement at 6 weeks (p = 0.03) in the GB group but this difference was not maintained. PROMs favoured the GB group, with the KOOS pain scoring statistically better (p ≤ 0.05) at 6 weeks, 3, 6 and 12 months. CONCLUSIONS: Individualised alignment philosophy utilising a GB technique did not demonstrate an improvement in the primary outcome measure quadriceps peak torque. Improvement was seen in the GB group in PROM pain scores that was significant, both statistically and clinically, out to at least 1 year. Gains that were seen in functional assessment with GB, although significant at some time points, were no longer significant at 1 year and no difference was seen in quads strength. Compared to a MR technique, the individualised GB technique appears to confer some improvement in pain, ROM and some functional tests following TKR in the short-term.

Complex Regional Pain Syndrome after Total Knee Arthroplasty is Rare and Misdiagnosis Potentially Hazardous-Prospective Study of the New Diagnostic Criteria in 100 Patients with No Cases Identified.

Previous studies suggest that complex regional pain syndrome (CRPS) occurs in up to 21% of patients following total knee arthroplasty (TKA). However, this diagnosis has a substantial impact on the patient's management if it is incorrect. We aimed to identify cases, using updated internationally accepted criteria, while investigating potential causes of misdiagnosis.We prospectively studied a consecutive series of 100 primary TKA patients. Each patient was assessed 6-week post-TKA. Pain levels were recorded with the presence of symptoms and signs of CRPS (Budapest Diagnostic Criteria) assessed in those with excessive pain. An alternative diagnosis was sought, in these patients, including the presence of neuropathic pain.We found no cases of CRPS (no patients had symptoms or signs in greater than two of four subgroups). Seventeen patients had excessive pain levels (nine had an alternative diagnosis explaining this). The commonest signs were sensory and sudomotor, whereas motor/trophic changes were not seen. Using a previous definition (Orlando Criteria), eight patients may have been diagnosed with CRPS. Over half of the patients with unexplained excessive pain had evidence of neuropathic pain.CRPS is a rare diagnosis following TKA using modern criteria. Isolated signs and symptoms may lead to the overdiagnosis of CRPS in the presence of unexplained pain following TKA. New diagnostic criteria, with strict definitions and treatment algorithms, are now accepted. Delays in managing more common causes (such as neuropathic pain) may negatively affect the patient's outcome.

The characterisation of unexplained pain after knee replacement.

BACKGROUND: The aims of this study were to characterise the pain experienced by patients with chronic pain after knee replacement (KR), in whom no apparent 'orthopaedic' problem could be identified, and to establish how many have pain sensitisation problems (including neuropathic pain). METHODS: A total of 44 patients were prospectively evaluated at a multidisciplinary tertiary referral clinic by an orthopaedic surgeon, pain specialist, rheumatologist and physiotherapist. These patients had been pre-screened by an orthopaedic surgeon to remove cases where there was an obvious cause of pain that could be treated with revision surgery. They were then followed up to find out whether any subsequent interventions had occurred. RESULTS: The mean time since surgery was 29 months (range: 3-108 months), and 18% were revision KR. Patients were evaluated for symptoms of nociceptive pain, allodynia, pains elsewhere and psychosocial factors. The patients were categorised into nociceptive pain 43% (n = 19), pain sensitisation 25% (n = 11) and mixed pain 32% (n = 14). Mean Visual Analogue Score (VAS) pain scores were 6.7/10 with high scores for both constant (66%) and intermittent (70%) pain elements, and pain caused high levels of interference with life. Fifty percent suffered depression and 25% suffered widespread pains (more than three pains elsewhere in the body). Patients with widespread pains suffered more pain (p = 0.01) and higher rates of both pain sensitisation (p = 0.07) and thermal allodynia (p < 0.04). CONCLUSION: Patients after KR can experience severe pain that interferes with their lives, depression and many have pain sensitisation problems rather than any local, nociceptive cause. We advocate screening patients with unexplained pain after KR for pain sensitisation problems, pains at other sites and depression. Appropriate further treatment and multidisciplinary interventions can then be arranged.

Compaction bone grafting in tibial plateau fracture fixation.

BACKGROUND: Displaced tibial plateau fractures are traditionally treated with internal fixation using autologous bone grafting to provide structural support. In comminuted and osteoporotic fractures, there can be insufficient autograft available for this. Fresh-frozen bone allograft is readily available in sufficient quantity to fill all voids, is relatively inexpensive, and avoids donor site morbidity. METHODS: We describe our technique and the early clinical and radiologic results of compaction morselized bone grafting (CMBG) for displaced tibial plateau fractures using fresh-frozen allograft. RESULTS: This technique has been performed since July 2006 on eight patients. One patient died of an unrelated cause 3 months after surgery and one patient failed to attend follow-up clinic. Clinical and radiologic follow-up was performed on the remaining six patients at an average 15 months (range, 12-19) after surgery. One patient underwent a manipulation under anesthesia at 3 months for knee stiffness. One patient developed a painless valgus deformity and underwent a corrective osteotomy at 15 months. The height of the tibial plateau on radiographs has been maintained to an excellent grade (less than 2 mm depression) in all but one patient. CONCLUSION: CMBG using fresh-frozen allograft in depressed tibial plateau fractures provides structural support sufficient to maintain the height of the tibial plateau, is associated with few complications in complex patients with large bone loss, and has theoretical advantages of graft incorporation and remodeling.