How to best measure femoral length and lateralisation after total hip arthroplasty on antero-posterior pelvic radiographs

Do Cementless Stems Match Any Hip? A Description of Anthropometric Measurements of the Proximal Femur in Colombia

Background

Leg length discrepancy following hip arthroplasty causes dissatisfaction to the patient; thus, preoperative planning and implant selection is critical. The purpose of this study was to measure the articular-trochanteric distance (ATD) and femoral neck length (FNL) in our population and compare them to those of 3 of the most used uncemented stems.

Methods

In this cross-sectional study, 401 hip radiographs of healthy adults were collected between January and July 2022. The vertical ATD and FNL were measured. A linear regression model was used to identify the relationship between these measurements and age, sex, and height. A logistic regression model was used to assess the matching of native hips with the neck length of the stem.

Results

Mean age was 60 years, and 74.56% were women. In 94.3% of hips, the ATD was negative, 3.73% neutral, and 2% positive. In our population, 0.25% of FNL were shorter than POLARSTEM (Smith & Nephew, UK), 10.72% shorter than MetaFix stem (Corin, UK), and 11.97% shorter than Corail stem (DePuy Synthes, USA). In the logistic regression analysis, matching for the POLARSTEM was associated with age but not with sex or height. Conversely, for MetaFix and Corail, stem matching was associated with sex and height.

Conclusions

Anthropometric hip measurements vary among individuals, and variables such as age, sex, and height must be considered during preoperative planning and implant selection to avoid leg length discrepancy. Additional studies, including different implants, are required to guide surgeons in selecting a femoral stem that best matches the patient's native hip.

No significant differences in 60-day postoperative complication rates between conventional and shortened stems

PURPOSE

To compare 60-day complication rates, radiographic outcomes, and clinical outcomes following primary THA with conventional versus shortened stems, in a large cohort study.

METHODS

The authors reviewed a consecutive series of 800 primary THAs, of which 781 met the inclusion/exclusion criteria: 395 received a conventional stem and 386 received a shortened stem. Intraoperative and postoperative complications were noted. Radiographic and clinical assessments were performed preoperatively and 60 days after surgery.

RESULTS

Compared to conventional stems, shortened stems had significantly less intraoperative complications (2.8% vs 0.3%, p = 0.006), but no significant differences in complications that did not require reoperation (1.0% vs 1.3%, p = 0.620), complications that required reoperation without stem revision (2.0% vs 1.0%, p = 0.384), and complications that required stem revision (0.5% vs 0.5%, p = 1.000). Four hips (two from each group) required stem revision and were thus excluded from 60-day assessment. There were no significant differences between groups in subsidence ≥ 3 mm (1.0% vs 0.5%, p = 0.686), alignment (90.3%vs 86.7%, p = 0.192), net change in offset (within 3 mm, 32.3% vs 30.5%, p = 0.097), and limb length discrepancy (3.0 ± 2.6 mm vs 2.9 ± 2.4 mm, p = 0.695). Compared to conventional stems, shortened stems had significantly better preoperative mHHS (56.5 ± 18.5 vs 64.5 ± 13.5, p < 0.001), and significantly lower net improvement in mHHS (29.9 ± 17.1 vs 24.4 ± 15.0, p < 0.001), but no significant differences in postoperative mHHS (87.3 ± 11.9 vs 89.4 ± 9.6, p = 0.109).

CONCLUSIONS

There were no significant differences between conventional and shortened stems in terms of postoperative complication rates, radiographic outcomes, and postoperative mHHS. However, patients implanted with shortened stems had less intraoperative complications, but lower net improvement in mHHS.

LEVEL OF EVIDENCE

Level IV, Retrospective comparative cohort study.

The optimization of the length of the lower limbs after hip arthroplasty

BACKGROUND

The purpose of this research was to evaluate the effectiveness of hip joint arthroplasty in patients with different correction of the length of the legs and identifying factors that influence the outcome.

MATERIAL AND METHODS

We analyzed 93 patients operated upon with an initial shortening of the limb length by more than 3 cm. The difference in the length of the limbs ranged from 3 to 12 cm, which averaged 5 cm. Immediately after surgery and after three to 12 months, a control examination was performed with measurement of the length of the lower extremities and the function of the joint, using the Harris scale.

RESULTS

The study revealed three versions of the result of the correction of the length of the limb after hip joint arthroplasty: saving limb shortening (n = 16 (17%) with HHS 80 (95% CI, 78.4 to 83.4%); full restoration of limb length (n = 70 (75,5%) with HHS 78 (95% CI, 74.6 to 80.2%); excess limb lengthening (n = 7 (7.5%) with HHS 68 (95% CI, 63.5 to 73.5%).

CONCLUSIONS

So that, incorrect lengthening of the lower limb during arthroplasty leads to lameness, discomfort, muscle tension, which ultimately leads to pain. Optimal result of hip arthroplasty and ensure the necessary amplitude of movements, it is advisable to use prediction criteria of the leveling of the limb length, which are: the duration of the disease, presence of consequences of previous operations, gender, age, degree of tissue rigidity, severity of hip-spine syndrome, and scoliotic deformity.

The association of leg length and offset reconstruction after total hip arthroplasty with clinical outcomes

BACKGROUND

Restoring native hip anatomy and biomechanics is important to create a well-functioning hip arthroplasty. This study investigated the association of hip offset and leg length after hip arthroplasty with clinical outcomes, including patient reported outcome measures, the Trendelenburg Test and gait analysis.

METHODS

In 77 patients undergoing primary hip arthroplasty for osteoarthritis (age mean = 65 SD = 11 years; BMI mean = 27 SD = 5 kg/m²), hip offset and leg length discrepancy were measured on anteroposterior radiographs. The Western Ontario & McMaster Universities Osteoarthritis Index, the Trendelenburg Test and gait were assessed preoperatively, and at 3 and 12 months postoperatively. An inertial measurement unit was used to derive biomechanical parameters, including spatiotemporal gait parameters and tilt angles of the pelvis. Relationships between radiographic and functional outcomes were investigated, and subgroups of patients with >15% decreased and increased femoral offset were analysed separately.

FINDINGS

Patient-reported function scores and clinical tests demonstrated a few significant, weak correlations with radiographic outcomes (Spearman's ρ range = 0.26-0.32; p < 0.05). Undercorrection of femoral offset was associated with lower patient-reported function scores and with more step irregularity as well as step asymmetry during gait. Postoperative leg length inequality was associated with increased frontal plane tilt angle of the pelvis during the Trendelenburg Test and increased sagittal plane motion of the pelvis during gait. Femoral offset subgroups demonstrated no significant differences for patient-reported function scores and outcomes of the Trendelenburg Test and gait analysis.

INTERPRETATION

Reduced hip offset and leg length discrepancy following hip arthroplasty seem to be marginally associated with worse clinical outcomes.

Femoral offset found not to affect metal ion levels in metal-on-metal total hip arthroplasty

BACKGROUND

Failure to restore femoral offset in metal on polyethylene total hip arthroplasty (THA) causes polyethylene wear and aseptic loosening. To our knowledge, no study to date has investigated the relationship between femoral offset and wear in metal-on-metal (MOM) THA.

AIMS

In this study, we investigated the relationship between femoral offset and wear by measuring circulating metal ion levels in MOM THA.

METHODS

In this retrospective study, we identified patients who had undergone MOM THA with the ASR XL system (DePuy International Ltd., Leeds, UK). Femoral offset was measured using anteroposterior radiographs, and circulating metal ion levels (cobalt and chromium) were recorded.

RESULTS

In total, 95 patients were included (68 males and 27 females). The mean age at the time of surgery was 64.9. Mean time from surgery to blood sampling was 15.4 months. No statistically significant relationship was found between femoral offset and cobalt (p = 0.313) or chromium (p = 0.401) ions.

CONCLUSION

It is known that failure to restore femoral offset during THA can lead to high rates of wear in metal-on-polyethylene articulations. In our study, no statistically significant relationship was found between femoral offset and serum cobalt or chromium ions. This study adds to the information available to surgeons regarding factors that increase wear in metal-on-metal total hip arthroplasty.

Total hip arthroplasty using direct anterior approach and dual mobility cup: safe and efficient strategy against post-operative dislocation

AIM

We hypothesize that a dual mobility cup can be safely used via the direct anterior approach, without increasing the risk of complications or incorrect positioning.

MATERIALS AND METHODS

This retrospective study compared 201 primary total hip arthroplasties using a dual mobility cup performed via direct anterior approach without a traction table, to 101 arthroplasties performed via posterolateral approach. Implant positioning, function scores, and early complications were recorded.

RESULTS

Implant positioning was appropriate in both groups, with a higher cup anteversion in direct anterior approach. The complications rates were similar in both groups, with no dislocation or infection.

CONCLUSION

The direct anterior approach without traction table associated with a dual mobility cup does not increase the risk of complications or non-optimal positioning of implants. This strategy is interesting for patients with high risk of post-operative dislocation.