Femoral osteochondroplasty can be performed effectively without the risk of avascular necrosis or femoral neck fractures in an experimental ovine FAI model

et al. 2018

Clin Orthop Relat Res

Background Prophylactic pinning of the asymptomatic and normal-appearing contralateral hip in patients with unilateral slipped capital femoral epiphysis (SCFE) remains controversial. Understanding the minimal 10-year clinical, functional, and radiographic outcomes of the contralateral asymptomatic hip in unilateral SCFE may be helpful in the decision regarding whether the benefits associated with potentially preventing a SCFE are outweighed by the risk of additional surgery. Questions/purposes Among patients with SCFE treated with prophylactic pinning of the asymptomatic and contralateral hip, we sought (1) to determine the complications and reoperations; (2) to evaluate the development of cam deformities and the frequency and severity of osteoarthritis progression; and (3) to characterize hip pain and function as measured by the Harris hip score (HHS) and the Hip Disability and Osteoarthritis Outcome Score (HOOS) at minimal 10-year followup. Methods Between 1998 and 2005 all patients with SCFE seen at our institution were treated with the modified Dunn procedure and all were offered prophylactic pinning of the contralateral asymptomatic hip. Of the 41 patients who The institution of one or more of the authors (MT) has received, during the study period, funding from the Swiss National Science Foundation. Each author certifies that neither he, nor any member of his immediate family, has funding or commercial associations (consultancies, stock ownership, equity interest, patent/licensing arrangements, etc) that might pose a conflict of interest in connection with the submitted article. Clinical Orthopaedics and Related Research® neither advocates nor endorses the use of any treatment, drug, or device. Readers are encouraged to always seek additional information, including FDA approval status, of any drug or device before clinical use. Each author certifies that his institution approved the human protocol for this investigation, that all investigations were conducted in conformity with ethical principles of research, and that informed consent for participation in the study was obtained.

Section: Discussionmentioning

confidence: 99%

What Is the Prevalence of Cam Deformity After Prophylactic Pinning of the Contralateral Asymptomatic Hip in Unilateral Slipped Capital Femoral Epiphysis? A 10-year Minimum Followup Study

Lerch

Novais

et al. 2018

Clin Orthop Relat Res

“…However, due to the spatial orientation of the pelvis in sheep, this should occur in the superior acetabulum and not posteroinferiorly as observed in our study. Similarly, an interruption of the femoral head blood supply after intertrochanteric osteotomy is unlikely, since it could be shown that the experimental FAI induction in sheep can be performed safely without the risk of avascular necrosis 29 . We interpret these results as proof that the peripheral chondral damage in the ovine FAI model is caused by inclusion type FAI with an opposed central contre-coup mechanism in hip extension.…”

Section: Table Imentioning

confidence: 99%

Proof of concept: hip joint damage occurs at the zone of femoroacetabular impingement (FAI) in an experimental FAI sheep model

Zurmühle

Osteoarthritis and Cartilage

Nuss

et al. 2019

Self Cite

Objective: In ovine hips chondrolabral damage as seen in cam-type femoroacetabular impingement (FAI) can be induced via an intertrochanteric varus osteotomy. However, it is yet to proven whether the observed cartilage damage is caused by a dynamic cam type impingement. Thus we asked, (1) whether actual cartilage damage observed after FAI induction in ovine hips occurs at the predicted, computed zone of FAI; (2) whether the extent of cartilage damage increases with ambulation time in this animal model? Design: In this experimental, controlled, comparative study 20 sheep underwent unilateral FAI induction through an intertrochanteric varus osteotomy. Preoperatively sheep underwent computed tomography to generate three-dimensional models of the osseous pelvis and femur. The models were used to predict impingement zones before and after simulated varus osteotomy using range of motion (ROM) analysis. Sheep were sacrificed after 14e40 weeks of ambulation. At sacrifice cartilage was inspected and (1) location of actual damage and computed impingement zones were compared; (2) Cartilage damage was compared between short-and long ambulation groups. Results: (1) The average location and the extent of peripheral and central cartilage lesions did not differ with the computed impingement zones (all P > 0.05). (2) Grades of central, posterior cartilage damage were more severe in the long-compared to the short ambulation group (2.2 ± 1.8 vs 0.4 ± 0.5; P ¼ 0.030). Conclusions: In this experimental ovine FAI model the surgical induction of an osseous impingement conflict between the femur and acetabulum causes cartilage damage at the zone of simulated FAI.

“…The surgical procedure and anesthesia were performed according to the institutional routine protocol for surgery in sheep [33,36]. Anesthesia was induced through a jugular catheter and via an intravenous, constant-rate infusion of propofol plus a maximum 5% isoflurane (Minrad Inc, Buffalo, NY, USA) inhalation.…”

Section: Description Of Experimentsmentioning

confidence: 99%

“…Using the same incision, we performed an intermuscular, anterior approach (interval between the gluteus medius and the minimus muscle) for exposure of the joint capsule. After an H-shaped capsulotomy, we performed the femoral osteochondroplasty with curved chisels and a high-speed burr (Air Pen Drive; DePuy Synthes) until impingement-free ROM was established [33]. This approach reportedly prevents laceration of the retinacular vessels, which ensure the vascular supply to the femoral head [33,40].…”

Section: Description Of Experimentsmentioning

confidence: 99%

See 1 more Smart Citation

Do dGEMRIC and T2 Imaging Correlate With Histologic Cartilage Degeneration in an Experimental Ovine FAI Model?

Arendt

Liechti

et al. 2018

Clin Orthop Relat Res

Background Biochemical MRI of hip cartilage such as delayed gadolinium-enhanced MRI of cartilage (dGEM-RIC) and T2 mapping is increasingly used to judge cartilage quality in the assessment of femoroacetabular impingement (FAI). The current evidence is sparse about which of these techniques yields a stronger correlation with histologic cartilage degeneration because of the difficulty in validating biochemical MRI techniques against histology in the clinical setting. Recently, an experimental ovine FAI model was established that induces chondrolabral damage and offers a validated platform to address these limitations. Questions/purposes In a sheep model, we asked: (1) Do dGEMRIC and/or T2 values of acetabular and femoral cartilage correlate with histologic cartilage degeneration as assessed with the Mankin score? (2) Do simultaneously measured dGEMRIC and T2 values correlate in an experimental ovine FAI model? Methods We performed an experimental pilot study on five female Swiss Alpine sheep (10 hips) that underwent postmortem MRI, including biochemical cartilage sequences, after a staged FAI correction had been performed on one side. No surgery was performed on the contralateral side, which The institution of one or more of the authors (BvR) has received, during the study period, funding from the Swiss National Science Foundation. One of the authors certifies that he (FS), or a member of his immediate family, has received or may receive grants, during the study period, in an amount of USD 10,000 to USD 100,000 from the Swiss National Science Foundation (Bern, Switzerland), outside the submitted work. One of the authors certifies that he (MT), or a member of his immediate family, has received or may receive grants, during the study period, in an amount of more than USD 1,000,001 from the Swiss National Science Foundation for the conduct of this work. Clinical Orthopaedics and Related Research® neither advocates nor endorses the use of any treatment, drug, or device. Readers are encouraged to always seek additional information, including FDA approval status, of any drug or device before clinical use. Each author certifies that his or her institution approved the animal protocol for this investigation and that all investigations were conducted in conformity with ethical principles of research.