The SLIM Study: Economic, Energy, and Waste Savings Through Lowering of Instrumentation Mass in Total Hip Arthroplasty.

BACKGROUND: Nearly 700,000 total hip arthroplasties (THAs) are annually performed in North America, costing the healthcare system >$15 billion and creating over 5 million tons of waste. This study aims to (1) assess satisfaction of current THA setup; (2) determine economic cost, energy cost, and waste cost of current setup and apply lean methodology to improve efficiency; and (3) design and test "Savings through Lowering of Instrumentation Mass (SLIM) setup" based on lean principles and its ability to be safely implemented into practice. METHODS: A Needs Assessment Survey was performed. After review and surgeon input, the "SLIM" set was designed, significantly reducing redundancy. Eighty patients were randomized to either Standard or SLIM setup. Operating room time, blood loss, perioperative adverse events and complications, cost/case, instrument weight (kg/case), total waste (kg/case), case setup time, and number of times and number of extra trays required were compared between groups. RESULTS: The SLIM setup was associated with the following savings: Cost = -$408.19/case; Energy = -7.16 kWh/case; Waste = -1.61 kg/case; Trays = -6 (758 kg/case). No differences in operating room time, blood loss, and complication rate were detected (P > .05) between groups. Setup time was significantly shorter with SLIM (P < .05) and extra instrumentation was opened in <5% of cases. CONCLUSION: A more "minimalist approach" to THA can be safely implemented. The SLIM setup is efficient and has been openly accepted by our allied staff. Such setup can lead to 1,610 kg reduction in waste, 7,160 kWh, and $408,190 in savings per 1,000 THAs performed.

Patient-specific anatomical and functional parameters provide new insights into the pathomechanism of cam FAI.

BACKGROUND: Femoroacetabular impingement (FAI) represents a constellation of anatomical and clinical features, but definitive diagnosis is often difficult. The high prevalence of cam deformity of the femoral head in the asymptomatic population as well as clinical factors leading to the onset of symptoms raises questions as to what other factors increase the risk of cartilage damage and hip pain. QUESTIONS/PURPOSES: The purpose was to identify any differences in anatomical parameters and squat kinematics among symptomatic, asymptomatic, and control individuals and if these parameters can determine individuals at risk of developing symptoms of cam FAI. METHODS: Forty-three participants (n = 43) were recruited and divided into three groups: symptomatic (12), asymptomatic (17), and control (14). Symptomatic participants presented a cam deformity (identified by an elevated alpha angle on CT images), pain symptoms, clinical signs, and were scheduled for surgery. The other recruited volunteers were blinded and unaware whether they had a cam deformity. After the CT data were assessed for an elevated alpha angle, participants with a cam deformity but who did not demonstrate any clinical signs or symptoms were considered asymptomatic, whereas participants without a cam deformity and without clinical signs or symptoms were considered healthy control subjects. For each participant, anatomical CT parameters (axial alpha angle, radial alpha angle, femoral head-neck offset, femoral neck-shaft angle, medial proximal femoral angle, femoral torsion, acetabular version) were evaluated. Functional squat parameters (maximal squat depth, pelvic range of motion) were determined using a motion capture system. A stepwise discriminant function analysis was used to determine which of the parameters were most suitable to classify each participant with their respective subgroup. RESULTS: The symptomatic group showed elevated alpha angles and lower femoral neck-shaft angles, whereas the asymptomatic group showed elevated alpha angles in comparison with the control group. The best discriminating parameters to determine symptoms were radial alpha angle, femoral neck-shaft angle, and pelvic range of motion (p < 0.001). CONCLUSIONS: In the presence of a cam deformity, indications of a decreased femoral neck-shaft angle and reduced pelvic range of motion can identify those at risk of symptomatic FAI.

Visually focusing on the far versus the near target during the putting stroke.

The purpose was to evaluate the traditional method, of visually focusing on the ball, in comparison to focusing on the hole, during the putting stroke. The study design consisted of a pretest, a 4-week practice period, and a posttest. Participants (n = 31, handicap: 18.7 ± 10.4) practised using only one of the two gaze techniques. Testing consisted of having all participants putt using both gaze techniques from both a 1.22 m and a 4 m distance. Five putts were executed for each gaze technique/putt length combination for a total of 20 putts in each testing session per participant. The kinematics of every putting stroke executed during testing (1240 strokes) were captured using a TOMI® system. There was a significant improvement in putting success for both groups following practice (P = 0.001). Practising while visually focusing on the hole, resulted in a statistically significant reduction in putter speed variability in comparison to practising while visually focusing on the ball (P = 0.017). Visually focusing on the hole did not meaningfully (nor statistically) affect the quality of impact as assessed by the variability in face angle, stroke path, and impact spot at the precise moment the putter head contacted the ball.