Influence of the mechanical environment upon the healing of segmental bone defects in the rat femur

Loss of large segments of bone creates critical size defects (CSDs). These fail to heal spontaneously and present major clinical challenges to orthopaedic surgeons. The research described in this thesis is based upon the hypothesis that the healing of CSDs is responsive to the ambient mechanical environment, and can be accelerated by mechanical modulation. This hypothesis was tested in rat, femoral CSDs treated with recombinant, human, bone morphogenetic protein-2. For this study I designed novel external fixators allowing experimental control over the local mechanical environment. These were characterised by extensive mechanical testing prior to evaluation in the rat model. Low stiffness fixators induced callus formation 9 days after surgery, whereas rigid fixation delayed it until 2 weeks. All defects were radiologically bridged after 3 weeks. Rats were euthanised after 8 weeks and the defects evaluated by a battery of imaging, mechanical and histological tests. All confirmed the superiority of the lowest stiffness fixators. Based upon these data, I hypothesised that healing would be improved by imposing low stiffness for the first two weeks of healing, followed by high stiffness for the remaining six weeks. The experimental data confirm that this regimen dramatically accelerated callus formation and maturation, and induced faster remodelling of endosteal and periosteal callus. This was associated with higher failure strength, fewer trabeculae, decreased callus size and thicker and more uniform distribution of new cortical bone. Histologically it was not possible to detect cartilage within the defects prior to the appearance of bone, suggesting that healing either does not occur through endochondral ossification, or that this process is very rapid. These data confirm that the healing of CSDs is highly responsive to the ambient mechanical environment, allowing the rate and quality of healing to be manipulated. This information will help develop more efficient ways to heal CSD clinically

Influence of the mechanical environment upon the healing of segmental bone defects in the rat femur

Loss of large segments of bone creates critical size defects (CSDs). These fail to heal spontaneously and present major clinical challenges to orthopaedic surgeons. The research described in this thesis is based upon the hypothesis that the healing of CSDs is responsive to the ambient mechanical environment, and can be accelerated by mechanical modulation. This hypothesis was tested in rat, femoral CSDs treated with recombinant, human, bone morphogenetic protein-2. For this study I designed novel external fixators allowing experimental control over the local mechanical environment. These were characterised by extensive mechanical testing prior to evaluation in the rat model. Low stiffness fixators induced callus formation 9 days after surgery, whereas rigid fixation delayed it until 2 weeks. All defects were radiologically bridged after 3 weeks. Rats were euthanised after 8 weeks and the defects evaluated by a battery of imaging, mechanical and histological tests. All confirmed the superiority of the lowest stiffness fixators. Based upon these data, I hypothesised that healing would be improved by imposing low stiffness for the first two weeks of healing, followed by high stiffness for the remaining six weeks. The experimental data confirm that this regimen dramatically accelerated callus formation and maturation, and induced faster remodelling of endosteal and periosteal callus. This was associated with higher failure strength, fewer trabeculae, decreased callus size and thicker and more uniform distribution of new cortical bone. Histologically it was not possible to detect cartilage within the defects prior to the appearance of bone, suggesting that healing either does not occur through endochondral ossification, or that this process is very rapid. These data confirm that the healing of CSDs is highly responsive to the ambient mechanical environment, allowing the rate and quality of healing to be manipulated. This information will help develop more efficient ways to heal CSD clinically.EThOS - Electronic Theses Online ServiceAO foundation (S-08-42G)GBUnited Kingdo

Subacromial Decompression in Patients With Shoulder Impingement With an Intact Rotator Cuff: An Expert Consensus Statement Using the Modified Delphi Technique Comparing North American to European Shoulder Surgeons

Purpose: To perform a Delphi consensus for the treatment of patients with shoulder impingement with intact rotator cuff tendons, comparing North American with European shoulder surgeon preferences. Methods: Nineteen surgeons from North America (North American panel [NAP]) and 18 surgeons from Europe (European panel [EP]) agreed to participate and answered 10 open-ended questions in rounds 1 and 2. The results of the first 2 rounds were used to develop a Likert-style questionnaire for round 3. If agreement at round 3 was ≤60% for an item, the results were carried forward into round 4. For round 4, the panel members outside consensus (>60%, <80%) were contacted and asked to review their response. The level of agreement and consensus was defined as 80%. Results: There was agreement on the following items: impingement is a clinical diagnosis; a combination of clinical tests should be used; other pain generators must be excluded; radiographs must be part of the workup; magnetic resonance imaging is helpful; the first line of treatment should always be physiotherapy; a corticosteroid injection is helpful in reducing symptoms; indication for surgery is failure of nonoperative treatment for a minimum of 6 months. The NAP was likely to routinely prescribe nonsteroidal anti-inflammatory drugs (NAP 89%; EP 35%) and consider steroids for impingement (NAP 89%; EP 65%). Conclusions: Consensus was achieved for 16 of the 71 Likert items: impingement is a clinical diagnosis and a combination of clinical tests should be used. The first line of treatment should always be physiotherapy, and a corticosteroid injection can be helpful in reducing symptoms. The indication for surgery is failure of no-operative treatment for a minimum of 6 months. The panel also agreed that subacromial decompression is a good choice for shoulder impingement if there is evidence of mechanical impingement with pain not responding to nonsurgical measures. Level of evidence: Level V, expert opinion

Platelet-rich plasma versus corticosteroids for the treatment of plantar fasciitis : a systematic review and meta-analysis

Please read abstract in the article.https://journals.sagepub.com/home/ajshj2022Orthopaedic Surger

Arthroscopic partial meniscectomy versus physical therapy for degenerative meniscus lesions: how robust is the current evidence? A critical systematic review and qualitative synthesis

The purpose of this systematic review was to investigate study quality and risk of bias for randomized trials comparing partial meniscectomy with physical therapy in middle-aged patients with degenerative meniscus tears.A systematic review of Medline, Embase, Scopus, and Google Scholar was performed from 1990 through 2017. The inclusion criteria were at least 1 validated outcome score, and middle-aged patients (40\ua0years and older) with a degenerative meniscus tear. Studies with a sham arm, and acute and concomitant injuries were excluded. Risk of bias was assessed with the Cochrane Risk of Bias Tool. The quality of studies was assessed with the Cochrane GRADE tool and quality assessment tool (Effective Public Health Practice Project). Publication bias was assessed by funnel plot and Egger's test. The I statistics was calculated a measure of statistical heterogeneity.Six studies were included, and all were assessed as having a high risk of bias. There was no publication bias (P\ua0= .23). All studies were downgraded (low, n\ua0= 5; very low, n\ua0= 1). The Effective Public Health Practice Project assessed 1 study as strong, 2 as moderate, and 3 as weak. The overall results demonstrated moderate to low quality of the included studies. The I statistic was 96.2%, demonstrating substantial heterogeneity between studies.The results of this systematic review strongly suggest that there is currently no compelling evidence to support arthroscopic partial meniscectomy versus physical therapy. The studies evaluated here exhibited a high risk of bias, and the weak to moderate quality of the available studies, the small sample sizes, and the diverse study characteristics do not allow any meaningful conclusions to be drawn. Therefore, the validity of the results and conclusions of prior systematic reviews and meta-analyses must be viewed with extreme caution. The quality of the available published literature is not robust enough at this time to support claims of superiority for either alternative, and both arthroscopic partial meniscectomy or physical therapy could be considered reasonable treatment options for this condition.Level II, systematic review of Level I and II studies

Author reply to"Consensus statement for shoulder impingement : to operate or not? Who to ask for the consensus panel"

No abstract available.http://www.elsevier.com/locate/asdhj2023Orthopaedic Surger

Inter- and intraclass correlations for three standard foot radiographic measurements for plantar surface angles. Which measure is most reliable?

Background: The purpose of this study was to evaluate the reliability and reproducibility of three commonly used radiographic measures for plantar surface angles. Methods: The calcaneal angle (CA), calcaneal pitch angle (CPA), and length-height index (LHI) was measured by three independent examiners on two occasions on lateral foot radiographs. Intra- and inter-rater correlations were calculated using a general linear estimate model and post-hoc tests for repeated measures. Bland–Altman's plots with limits of agreement were used for observer differences in scores. Results: The intra-class correlations for the CA ranged from 0.91 to 0.94, for the CPA from 0.93 to 0.98, and for the LHI from 0.96 to 0.97. The inter-class correlations were 0.80 for CA, 0.83 for CPA and 0.93 for LHI. Conclusions: The results of this study strongly suggest that the length-height index was the most consistent and reliable measure for arch height. Level of evidence: Diagnostic Level II, validity

The anatomical relationship of the common peroneal nerve to the proximal fibula and its clinical significance when performing fibular-based posterolateral reconstructions

PURPOSE : The common peroneal nerve (CPN) can be injured during fibular-based posterolateral reconstructions due to its close relationship to the neck of the fibula. Therefore, the purpose of this study was to observe the course of the CPN and its branches around the fibular head and neck and quantify the position in relation to relevant bony landmarks and observe the relation between tunnel drilling for posterolateral corner reconstruction and both the tunnel entry and exit at the proximal fibula and the CPN and its branches was observed. METHODS : In 101 (mean age = 70.6 ± 16 years) embalmed cadaver knees, the relationship between bony landmarks (tibial tuberosity, styloid process of fibula (APR)) and the CPN and its branches were established and 8 (M1–M8) distances from these landmarks measured; mean, SD and 95% CI were recorded. In 21 of these knees, a fibula tunnel was drilled as in PLC reconstruction and the association of the CPN and its branches to the tunnel entry and exit were judged by two independent observers. Fisher’s exact test of independence was used to determine significant differences between genders. Tunnel intersection was analysed in a binary yes/no fashion and was described in frequencies and percentages. RESULTS : The mean distance from the APR to where the CPN reaches the fibula neck (M1) was 31.4 ± 8.9 mm (CI:29.8–33.0); from the apex of the styloid process (APR) to where the CPN passes posterior to the broadest point of the fibular head (M3) was 21.7 ± 12.6 mm (CI:19.4–24.0); from the apex of the APR to the most proximal point of the CPN/CPN first branch in the midline of the fibular head (M2) was 37.0 ± 6.7 mm (CI: 35.4–37.7). Out of the 21 randomly selected knees for drilling, the first branch of the CPN was damaged at the tunnel entry point in 7 (33%), and in 5 knees (24%), the CPN was damaged at the tunnel exit. In one knee, at both the tunnel entry and exit, the first branch of the CPN and the CPN were intersected, respectively. CONCLUSION : The results of this study strongly suggest that the CPN is at risk when drilling the fibula tunnel performing fibula-based posterolateral corner reconstructions. The total injury rate was 57% with a 33% incidence of injury to the first branch of the nerve at the tunnel entry and 24% to the CPN at the tunnel exit. CLINICAL RELEVANCE : Due to the high incidence of injury, percutaneous placement of guide pins and tunnel drilling is not recommended. The nerve should be visualized and protected by either a traditional open approach or minimally invasive techniques. With a minimally invasive approach, the nerve should be identified at the fibula neck and then followed ante- and retrograde.https://link.springer.com/journal/402hj2022Anatom

The posterior horn of the medial and lateral meniscus both reduce the effective posterior tibial slope : a radiographic MRI study

PURPOSE : The purpose of this study was to quantify the posterior horn meniscal slope and determine its contribution to the reduction in posterior tibial slope. METHODS : Patients aged between 16 and 60 years and had intact menisci with no evidence of previous injury or surgery were included. Patients with radiological evidence of osteoarthritis Grade II–IV, any acute or chronic meniscus injuries, fractures, and ligamentous injuries were excluded. The posterior bony slope (PTS) and the meniscus slope (MS) of the posterior horns were measured at 25, 50, and 75% from the medial and lateral borders of the tibial plateau. RESULTS : 325 MR images (mean age 37.1 ± 10.9 years) were included. There were 194 males and 131 females, with 162 left and 163 right knees. The PTS in the medial compartment ranged from (−) 2.8° to 3.7° and from (−) 1.3° to 1.9° in the lateral compartment (p = 0.0001). The MS in the medial compartment ranged from 27.4° to 28.2°, and from 27.8° to 28.7° in the lateral compartment (p > 0.05). The differences between the medial and lateral knee compartment were statistically significant. At the 25% interval the p level was 0.037, at 50% p = 0.00001, and at 75% p = 0.0001. There were no significant between gender differences. CONCLUSIONS : The results of this study demonstrated a significant reduction in posterior tibial bone slope by the posterior horns of both the medial and lateral meniscus, from a mean of (−) 1° to 2° to a more horizontal anterior slope. The posterior bone slope was larger in the medial compartment by 1°, resulting in a smaller slope reduction in the lateral compartment.https://link.springer.com/journal/276hj2022AnatomyOrthopaedic Surger

The mechanical properties of fresh versus fresh/frozen and preserved (Thiel and Formalin) long head of biceps tendons : a cadaveric investigation

Human cadaveric specimens commonly serve as mechanical models and as biological tissue donors in basic biomechanical research. Although these models are used to explain both in vitro and in vivo behavior, the question still remains whether the specimens employed reflect the normal in vivo situation. The mechanical properties of fresh-frozen or preserved cadavers may differ, and whether they can be used to reliably investigate pathology could be debated. The purpose of this study was to therefore examine the mechanical properties of cadaveric long biceps tendons, comparing fresh (n = 7) with fresh-frozen (n = 8), formalin embalmed (n = 15), and Thiel-preserved (n = 6) specimens using a Universal Testing Machine. The modulus of elasticity and the ultimate tensile strength to failure was recorded. Tensile failure occurred at an average of 12 N/mm2 in the fresh group, increasing to 40.1 N/mm2 in the fresh-frozen group, 50.3 N/mm2 in the formalin group, and 52 N/mm2 in the Thiel group. The modulus of elasticity/stiffness of the tendon increased from fresh (25.6 MPa), to fresh-frozen (55.3 MPa), to Thiel (82.5 MPa), with the stiffest being formalin (510.6 MPa). Thiel-preserved and formalin-embalmed long head of biceps tendons and fresh-frozen tendons have a similar load to failure. Either the Thiel or formalin preserved tendon could therefore be considered as alternatives for load to failure studies. However, the Young’s modulus of embalmed tendons were significantly stiffer than fresh or fresh frozen specimens, and these methods might be less suitable alternatives when viscoelastic properties are being investigated.http://www.elsevier.com/locate/aanat2019-06-04hj2018AnatomyOrthopaedic Surger