Posterior or anterolateral approach in hip joint arthroplasty - Impact on frontal plane moment

Efficacy of Real-Time Feedback Exercise Therapy in Patients Following Total Hip Arthroplasty: Protocol for a Pilot Cluster-Randomized Controlled Trial

BACKGROUND

Osteoarthritis of the hip joint is an increasing functional and health-related problem. The most common surgical treatment is hip replacement to reduce pain and improve function. Rehabilitation after total hip arthroplasty (THA) is not regulated in Austria and mostly depends on the patient's own initiative and possibilities. Functional deficits, such as valgus thrust of the leg, functional Trendelenburg gait, or Duchenne limp, are characteristic symptoms before and, due to the performance learning effect prior to surgery, also after the operation. Addressing these deficits is possible through neuromuscular-focused exercise therapy. The efficacy of such therapy relies significantly on the quality of performance, the frequency of exercise, and the duration of engagement. Enhancing sustainability is achievable through increased motivation and real-time feedback (RTF) on exercise execution facilitated by digital feedback systems.

OBJECTIVE

This study will be performed to quantify the medium-term effectiveness of digital home exercise feedback systems on functional performance following THA.

METHODS

A clinical trial with a cluster-randomized, 2-arm, parallel-group design with an 8-week intervention phase and subsequent follow-ups at 3 and 6 months postsurgery will be conducted. Feedback during exercising will be provided through a blended-care program, combining a supervised group exercise program with a self-developed digital feedback system for home exercise. In total, 70 patients will be recruited for baseline. The primary outcome parameters will be the frontal knee range of motion, pelvic obliquity, and lateral trunk lean. Secondary outcomes will be the sum scores of patient-reported outcomes and relevant kinematic, kinetic, and spatiotemporal parameters.

RESULTS

The trial started in January 2024, and the first results are anticipated to be published by June 2025. RTF-supported home exercise is expected to improve exercise execution quality and therapeutic adherence compared to using paper instructions for excise guidance.

CONCLUSIONS

The anticipated findings of this study aim to offer new insights into the effect of a blended-care program incorporating digital RTF on exercise therapy after unilateral THA, in addition to knowledge on the functional status 3 and 6 months postsurgery, for further improvement in the development of rehabilitation guidelines following THA.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT06161194; https://clinicaltrials.gov/study/NCT06161194.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

PRR1-10.2196/59755.

The anatomical location of cystic pseudotumors and muscle atrophy in metal-on-metal resurfacing hip arthroplasty is related to the surgical approach used for implantation. A subgroup analyses of a randomized controlled trial

BACKGROUND

Pseudotumors and muscle atrophy have been associated with metal-on-metal (MoM) resurfacing hip arthroplasty (RHA). We aimed to investigate the influence of the anterolateral (AntLat) and the posterior (Post) surgical approach on the location, grade and prevalence of pseudotumors and muscle atrophy in MoM RHA.

PATIENTS AND METHODS

Forty-nine patients were randomized to MoM RHA by the AntLat (n = 25) or the Post (n = 24) approach at Aarhus University Hospital. Patients underwent metal artifact reduction sequence (MARS) magnetic resonance imaging (MRI) scans for investigation of location, grade and prevalence of pseudotumors and muscle atrophy. Plain radiographs, metal-ions concentrations and clinical outcome scores were evaluated to compare outcomes of the surgical approaches.

RESULTS

MRI-detected pseudotumors were seen in 7 of 18 patients (39%) in the AntLat group and in 12 of 22 patients (55%) in the Post group (p = 0.33). Pseudotumors were mainly located anterolaterally to the hip joint in the AntLat group and postero-lateral to the hip joint in the Post group. Higher grades of muscle atrophy of the caudal part of the gluteus medius and minimus (p < 0.004) were seen in the AntLat group, and higher grades of muscle atrophy of the small external rotators were seen in the Post group (p < 0.001). The AntLat group had higher anteversion angles of mean 15.3° (range 6.1-7.5) versus mean 11.5° (range 4.9-22.5) in the Post group (p = 0.02). Metal-ion concentrations and clinical outcome scores were similar between groups (p > 0.08).

CONCLUSION

Muscle atrophy and pseudotumor location after MoM RHA follow the surgical approach used for implantation. This knowledge may help differentiate between "normal postoperative appearance" and "MoM disease."

A new minimal-invasive approach for total hip replacement in sheep

BACKGROUND

Over the last 50 years arthroplasty became the gold-standard treatment for disabling conditions of the coxofemoral joint. Variations of anterior, lateral, and dorsal incision have been applied, but as each approach requires the incision and reflection of various muscles to gain adequate exposure of the joint results are still controversial.

OBJECTIVE

The purpose of this study was to develop a minimal-invasive, tissue-sparing approach in sheep with reduced risks in animal testing.

METHODS

12 mature sheep underwent hip surgery as part of a study to evaluate a hip resurfacing system. In line with the preliminary cadaveric tests a modified, minimal-invasive, musclepreserving surgical approach was sought after.

RESULTS

We developed a surgical approach to the coxofemoral joint in sheep using only blunt tissue dissection after skin incision without any limitations in joint exposure or increased blood loss/duration of surgery.

CONCLUSION

Even though limitations occur and femoral orientation in sheep differs from man, joint forces have similar relative directions to the bone with similar bony and vascular anatomy. Therefore, this minimal-invasive muscle preserving approach might be a safe and comparable alternative in still inevitable animal testing.

"Anterolateral" approach to the hip: a systematic review of the correct definition of terms

PURPOSE

The Watson-Jones interval plane between tensor fascia lata (TFL) and the gluteus medius (GM) has come back into fashion in the past few years - Röttinger described the anterolateral minimal invasive approach (ALMI) for use in total hip replacement, in which the standard Watson-Jones interval was used, but with a completely intermuscular plane. However, the term anterolateral is often still utilised to describe intramuscular approaches in which the GM was violated, thus creating a potential misunderstanding in the literature. Accordingly, we have designed a study to answer the following questions: (1) are there articles in the recent literature that use the term "anterolateral" to describe different approaches; (2) which would be the correct description of the anterolateral approach?

METHODS

We did a systematic review of the literature based on PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines, to look for peer reviewed papers of any evidence level focusing on the definition of anterolateral approach; MEDLINE and EMBASE were searched.

RESULTS

73 manuscripts met the criteria of the systematic search. 53 papers (72.6%) reported the term anterolateral approach to describe a complete intermuscular approach between the interval between GM and TFL. Nonetheless, in the remaining 20 papers (27.4%) the term anterolateral was used to describe intramuscular approaches in which the gluteus medius was violated.

CONCLUSION

In about 1 out of 4 papers in the recent literature, the term anterolateral was utilised to describe approaches that are completely different both in terms of anatomy and function.