The relationship between skeletal muscle serum markers and primary THA: a pilot study.

Various reports confirm elevations in serum markers associated with skeletal muscle injury after orthopaedic surgery in the absence of overt clinical manifestations of myocardial injury. We therefore measured the influence surgical approach has on these serum markers after primary THA. We nonrandomly enrolled 30 nonconsecutive patients undergoing THA in three groups of 10 based on current surgical approaches used at our facility: (1) minimally invasive (MIS) modified Watson Jones approach; (2) miniposterior transmuscular approach (MIS-I); and (3) MIS-II incision. Blood samples for hemoglobin, hematocrit, cardiac troponin I, total creatine kinase, creatine phosphokinase, and serum myoglobin were obtained the morning before surgery as a baseline, immediately postoperatively, and 72 hours thereafter. We found reproducible trends in serum enzyme levels consistent with skeletal muscle damage resulting from primary THA. Troponin I remained normal in all but one patient indicating no myocardial contribution to measured serum enzyme levels. All three procedures resulted in similar trends in serum enzyme markers relevant to primary THA. Our preliminary data suggest no surgical approach appears to affect the degree of muscle trauma more or less than another.

Early Clinical Outcomes of a New Cementless Total Knee Arthroplasty Design.

Cementless fixation design failures led to low use of this alternative technology. A cementless total knee arthroplasty addressed these design flaws. The single radius knee design incorporated additive manufacturing to produce the tibial and patellar implants. Both implants have enhanced porous substrates, optimizing initial bony ingrowth. A nonrandomized prospective review was conducted of 72 cementless knees followed for a minimum of 2 years (mean, 37 months). Surgical time, estimated blood loss, and range of motion at 6 weeks were compared with those of a matched cohort of 70 cemented knees performed by the same surgeon. Knee Society Score and Oxford Knee Score were recorded for the cementless group. Radiographs were evaluated for change in implant position, subsidence, and radiolucent and sclerotic lines. Operative time was statistically shorter in the cementless group (40 vs 45 minutes), but there was no significant difference in postoperative estimated blood loss (557 vs 355 mL). Range of motion at 6 weeks averaged 118° in the cementless group vs 114° in the cemented group. Knee Society Score improved from 53.9 preoperatively to 85.0 at 6 weeks and 91.6 at most recent follow-up. Oxford Knee Score improved from 23.9 preoperatively to 31.7 at 6 weeks and 43.4 at most recent follow-up. No implants aseptically loosened or migrated. There were 2 early infections in the cemented group requiring revision. This cementless total knee arthroplasty revealed excellent clinical results at 3-year follow-up and resulted in shortened operative times. Biologic fixation was achieved in 100% of patients with improved functional and objective scores. Early results are encouraging, and this cementless total knee arthroplasty appears to provide an excellent alternative to cemented total knee arthroplasty. [Orthopedics. 2018; 41(6):e765-e771.].