The Chitranjan S. Ranawat Award : No Difference in 2-year Functional Outcomes Using Kinematic versus Mechanical Alignment in TKA: A Randomized Controlled Clinical Trial.

BACKGROUND: Neutral mechanical alignment (MA) in total knee arthroplasty (TKA) aims to position femoral and tibial components perpendicular to the mechanical axis of the limb. In contrast, kinematic alignment (KA) attempts to match implant position to the prearthritic anatomy of the individual patient with the aim of improving functional outcome. However, comparative data between the two techniques are lacking. QUESTIONS/PURPOSES: In this randomized trial, we asked: (1) Are 2-year patient-reported outcome scores enhanced in patients with KA compared with an MA technique? (2) How does postoperative component alignment differ between the techniques? (3) Is the proportion of patients undergoing reoperation at 2 years different between the techniques? METHODS: Ninety-nine primary TKAs in 95 patients were randomized to either MA (n = 50) or KA (n = 49) groups. A pilot study of 20 TKAs was performed before this trial using the same patient-specific guides positioning in kinematic alignment. In the KA group, patient-specific cutting blocks were manufactured using individual preoperative MRI data. In the MA group, computer navigation was used to ensure neutral mechanical alignment accuracy. Postoperative alignment was assessed with CT scan, and functional scores (including the Oxford Knee Score, WOMAC, and the Forgotten Joint Score) were assessed preoperatively and at 6 weeks, 6 months, and 1 and 2 years postoperatively. No patients were lost to followup. We set sample size at a minimum of 45 patients per treatment arm based on a 5-point improvement in the mean Oxford Knee Score (OKS; the previously reported minimum clinically significant difference for the OKS in TKA), a pooled SD of 8.3, 80% power, and a two-sided significance level of 5%. RESULTS: We observed no difference in 2-year change scores (postoperative minus preoperative score) in KA versus MA patients for the OKS (mean 21, SD 8 versus 20, SD 8, least square means 1.0, 95% confidence interval [CI], -1.4 to 3.4, p = 0.4), WOMAC score (mean 38, SD 18 versus 35, SD 8, least square means 3, 95% CI, -3.2 to 8.9, p = 0.3), or Forgotten Joint score (28 SD 37 versus 28, SD 28, least square means 0.8, 95% CI, -9.1-10.7, p = 0.8). Postoperative hip-knee-ankle axis was not different between groups (mean KA 0.4° varus SD 3.5 versus MA 0.7° varus SD 2.0), but in the KA group, the tibial component was a mean 1.9° more varus than the MA group (95% CI, 0.8°-3.0°, p = 0.003) and the femoral component in 1.6° more valgus (95% CI, -2.5° to -0.7°, p = 0.003). Complication rates were not different between groups. CONCLUSIONS: We found no difference in 2-year patient-reported outcome scores in TKAs implanted using the KA versus an MA technique. The theoretical advantages of improved pain and function that form the basis of the design rationale of KA were not observed in this study. Currently, it is unknown whether the alterations in component alignment seen with KA will compromise long-term survivorship of TKA. In this study, we were unable to demonstrate an advantage to KA in terms of pain or function that would justify this risk. LEVEL OF EVIDENCE: Level I, therapeutic study.

Enhancing Postoperative Rehabilitation Following Knee Arthroplasty Using a New Cryotherapy Product: A Prospective Study.

To compare a novel cooling product, Physicool (P, Physicool Ltd, London, England, UK) with a well-established cryotherapy system, Cryocuff (C, Aircast, DJO Global, Vista, California, USA) using pain scores, range of movement (ROM), and cost as outcome measures in the early phase following total knee arthroplasty. We prospectively studied 90 consecutive patients undergoing unilateral total knee arthroplasty by a single surgeon. Following exclusions, 40 patients were recruited to each group. Visual analogue scale (VAS) for pain and ROM before and after application of cooling device was recorded at 24 and 48 hours after surgery. The cost of treatment per patient was also calculated. The VAS were significantly reduced in P on day 1 postsurgery (p = 0.013) and day 2 (p = 0.001) compared to C. A significant increase in ROM was recorded in P at 24 hours (p = 0.004) and at 48 hours (p = 0.009) postsurgery compared to C. The cost benefit of using P over C was approximately £25 per patient. The Physicool system is a safe and effective cooling method for improving pain and ROM in the early postoperative phase following total knee arthroplasty. Furthermore, it offers substantial cost savings.

The Mark Coventry Award: Higher tissue concentrations of vancomycin with low-dose intraosseous regional versus systemic prophylaxis in TKA: a randomized trial.

BACKGROUND: In response to increasing antibiotic resistance, vancomycin has been proposed as an alternative prophylactic agent in TKA. However, vancomycin requires a prolonged administration time, risks promoting further antibiotic resistance, and can cause systemic toxicity. Intraosseous regional administration (IORA) is known to achieve markedly higher antibiotic concentrations than systemic administration and may allow the use of a lower vancomycin dose. QUESTIONS/PURPOSES: We assessed whether low-dose IORA vancomycin can achieve tissue concentrations equal or superior to those of systemic administration in TKA and compared complications between patients treated with IORA and intravenous vancomycin. METHODS: We randomized 30 patients undergoing primary TKA to receive 250 or 500 mg vancomycin via IORA or 1 g via systemic administration. IORA was performed as a bolus injection into a tibial intraosseous cannula below an inflated thigh tourniquet immediately before skin incision. Subcutaneous fat and bone samples were taken during the procedure and antibiotic concentrations measured. RESULTS: The overall mean tissue concentration of vancomycin in subcutaneous fat was 14 µg/g in the 250-mg IORA group, 44 µg/g in the 500-mg IORA group, and 3.2 µg/g in the systemic group. Mean concentrations in bone were 16 µg/g in the 250-mg IORA group, 38 µg/g in the 500-mg IORA group, and 4.0 µg/g in the systemic group. One patient in the systemic group developed red man syndrome during infusion. CONCLUSIONS: Low-dose IORA vancomycin results in tissue concentrations equal or superior to those of systemic administration. IORA optimizes timing of vancomycin administration, and the lower dose may reduce the risk of systemic side effects while providing equal or enhanced prophylaxis in TKA.

Thromboprophylaxis in trauma: a review of methods, evidence and guidelines.

Venous thromboembolism is a common cause of morbidity and mortality in trauma patients. Mechanical and pharmacological methods of thromboprophylaxis are available and guidelines relating to thromboprophylaxis in trauma include those published by the American College of Chest Physicians, the UK-based National Institute of Clinical Excellence, the Scottish Intercollegiate Guidelines Network and US-based Eastern Association for the Surgery of Trauma. All four guidelines have in common a recommendation for the use of low-molecular-weight heparin except where contraindicated. However, there is little consensus between guidelines relating to which mechanical methods should be used. Given the risk of thromboembolism in trauma patients and increasing interest in this condition clinicians should be aware of local and national guidelines relating to venous thromboembolism prevention in trauma patients. This paper reviews methods of thromboprophylaxis and compares guidelines relating to their use in trauma patients.