Sensor-to-Bone Calibration with the Fusion of IMU and Bi-Plane X-rays.

Inertial measurement units (IMUs) need sensor-to-segment calibration to measure human kinematics. Multiple methods exist, but, when assessing populations with locomotor function pathologies, multiple limitations arise, including holding postures (limited by joint pain and stiffness), performing specific tasks (limited by lack of selectivity) or hypothesis on limb alignment (limited by bone deformity and joint stiffness). We propose a sensor-to-bone calibration based on bi-plane X-rays and a specifically designed fusion box to measure IMU orientation with respect to underlying bones. Eight patients undergoing total hip arthroplasty with bi-plane X-rays in their clinical pathway participated in the study. Patients underwent bi-plane X-rays with fusion box and skin markers followed by a gait analysis with IMUs and a marker-based method. The validity of the pelvis, thigh and hip kinematics measured with a conventional sensor-to-segment calibration and with the sensor-to-bone calibration were compared. Results showed (1) the feasibility of the fusion of bi-plane X-rays and IMUs in measuring the orientation of anatomical axes, and (2) higher validity of the sensor-to-bone calibration for the pelvic tilt and similar validity for other degrees of freedom. The main strength of this novel calibration is to remove conventional hypotheses on joint and segment orientations that are frequently violated in pathological populations.

Does Revision Carpal Tunnel Release Result in Long-Term Outcomes Equivalent to Single Carpal Tunnel Release? A Matched Case-Control Analysis.

BACKGROUND: The aims of this study were to evaluate long-term patient-reported outcomes after revision carpal tunnel release (CTR); compare these outcomes with those of patients who had a single CTR and a comparable age, sex, race, type of initial surgery, and follow-up time; and assess which factors are associated with worse patient-reported outcomes after revision CTR. METHODS: The authors retrospectively identified 7351 patients who had a single CTR and 113 patients who had a revision CTR for carpal tunnel syndrome between January of 2002 and December of 2015 at five academic urban hospitals. Of these 113 revision CTR cases, 37 patients completed a follow-up questionnaire including the Boston Carpal Tunnel Questionnaire (BCTQ), the Numerical Rating Scale for Pain Intensity, and satisfaction score. Those who completed the follow-up questionnaire were randomly matched to five controls (patients who had a single CTR) based on age, sex, race, type of initial surgery, and follow-up time. Of these 185 matched controls, 65 completed the follow-up questionnaire. RESULTS: A linear mixed effects model using matched sets as a random effect showed that patients who had a revision CTR had a higher total BCTQ score, Numerical Rating Scale for Pain Intensity score, and a lower satisfaction score at time of follow-up than patients who had a single CTR. Multivariable linear regression showed that thenar muscle atrophy before the revision surgery was independently associated with more pain after revision surgery. CONCLUSION: Patients improve after revision CTR, but generally have more pain, have a higher BCTQ score, and are less satisfied at long-term follow-up compared with patients who had a single CTR.

The modern state of femoral, acetabular, and global offsets in total hip arthroplasty: a narrative review.

Offsets in the frontal plane are important for hip function. Research on total hip arthroplasty (THA) surgery agrees that increasing femoral offset up to 5 mm could improve functional outcome measures. The literature indicates that global offset is a key parameter that physicians should restore within 5 mm during surgery and avoid decreasing. Substantiated findings on acetabular offset are lacking despite its recognized importance, and the medialization approach must be assessed in light of its shortcomings. Future research, possibly through improved measurement, unified definitions, patient-specific surgical planning, and technology-enhanced surgical control, with specific focus on acetabular offset, is needed to better understand its impact on THA outcomes.

Definition and reliability of 3D acetabular and global offset measurements from bi-plane X-rays.

The importance of the global offset, the sum of femoral and acetabular offset, has been underlined in the literature as a key factor for the functional outcome of total hip arthroplasty (THA). However, the acetabular offset is not defined for bi-plane X-rays, a technology providing 3D measurements of the lower limb and commonly used for patients undergoing THA. The aim of this paper is to introduce a measurement method of the 3D acetabular offset with bi-plane X-rays. Our method combines the use of technical and anatomical coordinate systems. The most appropriate definition will be selected based on the best reliability and measurement error. The consequent reliability of the global offset was also assessed. Twenty-eight patients undergoing primary THA were selected retrospectively. Two operators performed three reconstructions for each patients before and after THA. Intraclass correlation (ICC) and smallest detectable change (SDC) were computed for intra-operator, inter-operator and test-retest conditions for all combinations of technical and anatomical coordinate systems. ICCs were good to excellent. One combination was more reliable than others with a moderate mean SDC of 6.3 mm (4.3-8.7 mm) for the acetabular offset and a moderate mean SDC of 6.2 mm (5.6-6.7 mm) for the global offset. This is similar to the reliability and mean SDC of the femoral offset (4.8 mm) approved for clinical use which indicates that this method of acetabular offset measurement is appropriate. This opens a research avenue to better understand the role of the acetabular offset on THA outcomes, which seems overlooked in the literature.

Patient-Reported Outcomes After Surgical Treatment of Early Osteoarthritis of the First Carpometacarpal Joint.

BACKGROUND: The goals of this study are to describe the reoperation rates in patients who underwent Wilson osteotomy compared with patients who underwent carpometacarpal (CMC) arthroplasty for early-stage arthritis and to evaluate the factors influencing the patient-reported outcomes. METHODS: Retrospectively, 52 patients who underwent surgery for stage I/II osteoarthritis of the thumb carpometacarpal were identified, consisting of 17 (33%) patients who underwent Wilson osteotomy and 35 (67%) who underwent carpometacarpal arthroplasty. A total of 28 (55%) patients completed the outcome questionnaires, consisting of 11 (39%) patients who underwent Wilson osteotomy and 17 (61%) patients who underwent carpometacarpal arthroplasty. We performed a multivariable linear regression model to identify factors associated with the Numeric Rating Scale (NRS) pain intensity at final follow-up. RESULTS: Among the patients who underwent CMC arthroplasty, 2 had a reoperation. Among the patients who underwent Wilson osteotomy, 3 had a reoperation. Among the patients who completed the outcome questionnaires, the median quick Disabilities of the Arm, Shoulder and Hand score was 10 and the median NRS Pain Intensity score was 0. In multivariable analysis, the postoperative Patient-Reported Outcomes Measurement Information System Pain Interference (PROMIS PI) was independently associated with higher postoperative NRS pain scores. CONCLUSION: In younger patients with stage I/II CMC osteoarthritis, Wilson osteotomy may be a reasonable alternative to CMC arthroplasty. Outcomes were similar between both groups at mid-term follow-up, with only a slightly higher pain score in the osteotomy group. In patients with stage I/II carpometacarpal osteoarthritis, the PROMIS PI is the main factor indicating successful outcomes.

Reliability of the pelvis and femur anatomical landmarks and geometry with the EOS system before and after total hip arthroplasty.

Bi-plane X-ray provides 3D measurements of the lower limb based on the identification of anatomical landmarks in sagittal and frontal X-rays. In clinical practice, such measurements involve multiple operators and sessions. This study aimed at evaluating the reliability of anatomical landmarks identification and geometric parameters of the pelvis and femur measured with bi-plane X-rays before and after total hip arthroplasty (THA). Twenty-eight patients undergoing primary THA were selected retrospectively. Two operators performed three reconstructions for each patient before and after THA. Intraclass correlation (ICC) and smallest detectable change (SDC) were computed for intra-operator, inter-operator, and test-retest conditions. Most anatomical landmark positions had good to excellent SDC (< 5 mm) apart from the centre of the sacral slope, greater trochanter, and anterior superior iliac spines (up to 7.1, 16.9, and 21.5 mm respectively). Geometric parameters had moderate to excellent SDC, apart from femoral and stem torsion, pelvic incidence, and APP inclination with poor SDC (9-12°). The sagittal view had significantly higher measurement errors than the frontal view. Test-retest and inter-operator conditions had no significant differences suggesting a low influence of patient posture. Osteoarthritis and the presence of implants did not seem to influence reliability and measurement error. This study could be used as a reference when assessing lower limb structure with bi-plane X-rays.