Volker Musahl

• Professor
• Managing Director at University of Pittsburgh

Purpose To assess the outcomes of surgical management of patellar instability in hypermobile patients. Methods Three online databases (PubMed, MEDLINE and EMBASE) were searched from inception to 27 September 2024, to identify studies investigating the surgical management options for patellar instability in hypermobile patients. Data pertaining to...

Background Primary anterior cruciate ligament reconstruction (ACLR) using quadriceps tendon (QT) autograft may increase the risk for postoperative loss of extension, although it is unclear if this is due to QT autograft diameter. Purpose To document the rate of >5° loss of knee extension after QT autograft ACLR and determine associations between l...

Purpose This study aims to assess anterior cruciate ligament reconstruction (ACLR) outcomes and return to pre‐injury sports (RTPS) characteristics in athletes participating in martial arts. Methods Martial arts athletes over the age of 14 years who underwent primary ACLR with a minimum 1‐year follow‐up were eligible for this study. This study defi...

Background When injuring the anterior cruciate ligament (ACL), simultaneous meniscal tears often occur. However, little data describe ACL reconstruction (ACLR) and the subsequent risk of revision ACLR, as well as cartilaginous and meniscal damage after primary ACLR with different treatments for injury of the lateral meniscus (LM). Purpose To inves...

Isolated anterior cruciate ligament (ACL) injuries are common but more frequently present with accompanying pathologies. There is a wide range of associated pathologies from various meniscal tears and cartilage lesions to multiligament knee injuries. When counseling patients about their ACL injury and recovery, it is important to have a good unders...

The anterior cruciate ligament (ACL) functions to provide translational and rotatory stability of the knee. ACL injury is diagnosed through a combination of history, physical examination, and imaging, and can be treated successfully with both operative and nonoperative approaches. However, persistent knee instability following a trial of nonoperati...

Artificial intelligence (AI) has been influencing healthcare and medical research for several years and will likely become indispensable in the near future. AI is intended to support healthcare professionals to make the healthcare system more efficient and ultimately improve patient outcomes. Despite the numerous benefits of AI systems, significant...

Level of Evidence Level V.

The current study investigated the relationship between sensorimotor cortical thickness, corticospinal excitability, corticomotor topography, and quadriceps strength after ACL reconstruction (ACLR). Ten women with a history of unilateral ACLR and 10 controls (CON) received single-pulse transcranial magnetic stimulation during unilateral, submaximal...

Revision surgery after anterior cruciate ligament reconstruction (ACL‐R) is hypothesized to be the result of an interplay between factors associated with the anatomy, physiological characteristics and environment of the patient. The multifactorial nature of revision ACL‐R risk is difficult to quantify, and evidence regarding the independent roles o...

In surgical trials, safety monitoring should be prioritized during each stage of the study to ensure potential treatment benefits outweigh harms to patients. Many regulatory bodies require reporting of adverse events (AEs), serious adverse events (SAEs), and unanticipated problems (UAPs). The following chapter defines these terms in the context of...

The duration of follow-up, which is the time that contact is maintained with study participants so that information can be collected to determine the effects of a given intervention, is a fundamental and important part of surgical trials. Appropriate follow-up is determined during trial design. Failure to determine adequate follow-up period can com...

Background: Postoperative infection following anterior cruciate ligament reconstruction (ACLR) is a rare yet severe complication that can compromise patient outcomes, leading to prolonged recovery, graft failure, and knee dysfunction. Although infection rates are reported to be less than 2%, it remains essential to implement strategies to reduce in...

Purpose To quantify the effect of increasing the posterior tibial slope (PTS) on knee kinematics and the resultant medial and lateral meniscal forces. Methods In this controlled laboratory study, a 6 degrees of freedom (DOF) robotic testing system was used to apply external loading conditions to seven fresh‐frozen human cadaveric knees: (1) 200‐N...

Background The rate of subjective failure after isolated primary posterior cruciate ligament reconstruction (PCL-R) is relatively high, requiring an improved understanding of factors associated with inferior outcomes. Purpose To determine the association between patient and injury-related factors and total (surgical and clinical) failure at 2 year...

Osteotomies around the knee have a variety of indications, including pain reduction, functional improvement, knee joint stabilization, and articular cartilage preservation. Thorough preoperative planning is essential, including a determination of the precise location of any deformity (proximal tibia, distal femur, or both). High tibial osteotomies...

Purpose The use of patient-reported outcome measures (PROMS) is the cornerstone of clinical research for surgical disciplines, but the use in daily routine can be challenging. One of the most widespread PROMS in knee surgery is the International Knee Documentation Committee (IKDC) questionnaire. The purpose of the present study was to investigate t...

BACKGROUND: Little evidence exists regarding the return to sport outcomes of American football players following multiligament knee injuries (MLKI), specifically following an injury that does not include the anterior cruciate ligament (ACL). CASE PRESENTATION: The patient is a 22-year-old American football offensive lineman, who sustained a posteri...

Objectives To identify predictive factors for successful return to sport (RTS) following anterior cruciate ligament reconstruction (ACL-R) with quadriceps tendon (QT) autograft. Methods Data was retrospectively collected on consecutive patients who underwent ACL-R with QT autograft at a single institution between 2010-2020. Patient demographics, k...

Background Despite a growing body of literature regarding anterior cruciate ligament reconstruction (ACLR), there remains a wide diversity in surgical technique and clinical practice across providers. Purpose To (1) describe current ACLR practice preferences among members of the Herodicus society and (2) determine whether these preferences are inf...

Anterior cruciate ligament (ACL) injuries continue to increase in incidence despite extensive research into prevention strategies. Many extrinsic and intrinsic risk factors for sustaining ACL injuries have been identified and continue to be investigated. Extrinsic risk factors for ACL injury relate to the athlete's environment, such as the shoe-sur...

Objectives This study aimed to compare demographic and surgical characteristics between patients who do and do not achieve minimal important change (MIC) in the Knee injury and Osteoarthritis Outcome Score (KOOS) Sports and Recreation (Sport/Rec) and Quality of Life (QoL) subscales 1 year after anterior cruciate ligament reconstruction. Design Com...

Multiligament knee injuries (MLKIs) represent a broad spectrum of pathology with potentially devastating consequences. Currently, disagreement in the terminology, diagnosis and treatment of these injuries limits clinical care and research. This study aimed to develop consensus on the nomenclature, diagnosis, treatment and rehabilitation strategies...

Background The healthcare sector in the United States has increased its greenhouse gas emissions by 6% since 2010 and today has the highest per capita greenhouse gas emissions globally. Assessing the environmental impact and material use through the methods of life cycle assessment (LCA) and material flow analysis of healthcare procedures, product...

Purpose of Review To provide an overview of the current evidence of the timing of surgery and rehabilitation after multiligamentous knee injuries (MLKIs) and offer insights into the ongoing multi-center randomized controlled study, the ‘STaR trial’. Recent Findings Due to the complexity of the MKLIs, they are usually treated surgically with the go...

Background Smaller intercondylar notch sizes have been consistently associated with a predisposition for primary anterior cruciate ligament tears. Purpose To evaluate the association between intercondylar notch size, graft size, and postoperative complications, including knee stiffness and return to the operating room, after primary anatomic anter...

Objectives Bony morphology has been proposed as a potential risk factor for anterior cruciate ligament (ACL) injury. There have been several reports on the relationship between bony morphology and knee kinematics, however, no reports have investigated if knee bony morphological parameters that are associated with knee kinematics are also associated...

Objectives Fatty infiltration and rotator cuff atrophy has been associated with poor clinical outcomes during rotator cuff repairs. Compared to supraspinatus and infraspinatus atrophy there has been minimal research on the effect of teres minor atrophy on surgical outcomes and failure rates in rotator cuff repairs. The purpose of this study was to...

Objectives Several factors have been implicated in the development of cyclops lesions after anterior cruciate ligament reconstruction (ACLR), including patient sex, concomitant meniscus repair, and graft choice (namely patellar tendon and quadriceps tendon autografts). However, the impact of surgical characteristics such as graft diameter, notch si...

Objectives The quadriceps tendon (QT) autograft has garnered popularity for anterior cruciate ligament (ACL) reconstruction (ACLR) in the last decade. However, as with other autograft choices, re-ruptures of QT autografts can occur especially in high-level athletes, with reported rates ranging from 2%-22%. ACL revision surgery is an option for thes...

Objectives Reaching the Patient-Acceptable Symptom State (PASS) threshold for the Knee injury and Osteoarthritis Outcome Score (KOOS) has previously been reported to successfully identify individuals experiencing clinical success after anterior cruciate ligament reconstruction (ACLR). Thus, the objectives of this study were to examine and compare t...

Revision anterior cruciate ligament reconstruction (ACLR) may present a challenge as a result of several factors, including malpositioned bone tunnels, tunnel osteolysis, and the presence of previous hardware. In addition, concomitant pathology, specifically meniscal and cartilaginous injuries, may be present and should be addressed to minimize the...

Posterior tibial slope (PTS) of ≥12˚ represents an important risk factor for both anterior cruciate ligament (ACL) injury and ACL reconstruction failure. PTS measurements can significantly differ on the basis of the imaging modality and the measurement technique used. PTS should be measured on strictly lateral radiographs, with a recommended proxi...

The objectives of this study were to evaluate the reliability of cartilage T2 relaxation time measurements and to identify focal changes in T2 relaxation on the affected knee from 6 to 24 months after anatomic anterior cruciate ligament reconstruction (ACLR). Data from 41 patients who received anatomic ACLR were analyzed. A bilateral 3.0‐T MRI was...

A bone bruise is generated by a bony collision that could occur when the ACL is injured, and its pattern supposedly depends on the injury mechanism and level of skeletal maturity. The objective of this study was to determine the effect of material properties and knee position on the bone bruise pattern in skeletally mature and immature subjects usi...

Purpose To determine whether scapular morphology could predict isolated supraspinatus tendon tear propagation after exercise therapy. We hypothesised that a larger critical shoulder angle (CSA) and type III acromial morphology predict a positive change in tear size. Methods Fifty‐nine individuals aged 40–70 years with isolated symptomatic high‐gra...

Purpose The purpose of this study was to identify risk factors for subsequent meniscal surgery following anterior cruciate ligament (ACL) reconstruction (ACLR) in patients without recurrent ACL injury. Methods Patients aged ≥14 years who underwent primary ACLR with minimum 1‐year follow‐up and without recurrent ACL injury were retrospectively revi...

Background Glenoid bone grafting procedures are often utilized to address glenoid bone loss in patients with recurrent shoulder instability. The purpose of this study was to determine if preoperative advanced imaging can accurately predict coracoid graft size and conversion of off-track to on-track Hill-Sachs lesions in patients undergoing Latarjet...

Artificial intelligence's (AI) accelerating progress demands rigorous evaluation standards to ensure safe, effective integration into healthcare's high‐stakes decisions. As AI increasingly enables prediction, analysis and judgement capabilities relevant to medicine, proper evaluation and interpretation are indispensable. Erroneous AI could endanger...

Background The timing of return to work (RTW) after anterior cruciate ligament (ACL) reconstruction (ACLR) is a less studied milestone compared with return to sports. Purpose To systematically review the rate and postoperative timing of RTW after ACLR. Study Design Systematic review; Level of evidence, 4. Methods This study was conducted in acco...

The exploration of underlying biological risk factors for anterior cruciate ligament (ACL) injury has generated a substantial body of literature describing the role of bony morphology of the knee. Morphological risk factors, such as poor tibiofemoral joint congruity, a narrow femoral intercondylar notch, and an increased posterior tibial slope (PTS...

Purpose To retrospectively compare strength outcomes of individuals undergoing postoperative rehabilitation following quadriceps tendon (QT) autograft anterior cruciate ligament reconstruction (ACLR) with and without blood flow restriction therapy. Methods A retrospective review of consecutive patients undergoing ACLR with QT autograft with a mini...

Purpose To describe rates of conversion to unicompartmental or total knee arthroplasty (KA) in patients over the age of 40 years (at initial surgery) after partial meniscectomy (ME) or meniscal repair (MR). Methods Patients over the age of 40 undergoing isolated ME or MR between 2016 and 2018 were extracted from a single healthcare provider databa...

Background While the pivot shift examination is often regarded as the gold standard test for diagnosis of anterior cruciate ligament (ACL) injury, one of the pitfalls of the pivot shift test is that it lacks standardization among physicians. The PIVOT App is a validated application to quantify the amount of tibial translation during the pivot shift...

Purpose The aim of this study was to investigate whether the whole tibial spine volume and femoral intercondylar notch volume are risk factors for anterior cruciate ligament (ACL) injury. The hypothesis was that the whole tibial spine volume and femoral notch volume would be smaller in athletes who sustained ACL injury than in athletes with no hist...

Background Diminished postoperative knee extension strength may occur after anterior cruciate ligament reconstruction (ACLR) with quadriceps tendon (QT) autograft. Factors influencing the restoration of knee extensor strength after ACLR with QT autograft remain undefined. Purpose To identify factors that influence knee extensor strength after ACLR...

Objectives Recent studies have shown that a subset of on-track Hill-Sachs lesions (HSL), defined as near-track lesions, may have a high risk of failure after primary arthroscopic Bankart repair (ABR) alone. The aim of this study was to evaluate rates of recurrent shoulder instability among patients with on-track HSL who underwent primary ABR with a...

Objectives Given the high rates of recurrent instability following the initial arthroscopic Bankart repair (ABR), it is crucial to provide recommendations for appropriate surgical interventions for patients at a higher risk of experiencing recurring instability. In Part 1 of the study, it was discovered that on-track Hill-Sachs lesions (HSL) with s...

Background Knee instability due to posterior cruciate ligament (PCL) and posterolateral corner (PLC) deficiency is a devastating condition that negatively affects patient quality of life. This video presents the surgical management of a triple varus knee, including combined high tibial osteotomy (HTO), revision PCL and PLC reconstruction, and menis...

Background Different fixation methods in anterior cruciate ligament reconstruction (ACLR) have been associated with different revision rates, specifically in the early postoperative period. However, most previous research has either grouped together different fixation types or evaluated femoral-sided fixation or tibial-sided fixation separately. Th...

Background Graft failure after anterior cruciate ligament reconstruction (ACLR) is a debilitating complication often requiring revision surgery. It is widely agreed upon that functional knee outcomes after revision ACLR (r-ACLR) are inferior compared with those after primary reconstruction. However, data are scarce on outcomes after multiple-revisi...

Aims The aim of this study was to establish consensus statements on the diagnosis, nonoperative management, and indications, if any, for medial patellofemoral complex (MPFC) repair in patients with patellar instability, using the modified Delphi approach. Methods A total of 60 surgeons from 11 countries were invited to develop consensus statements...

Aims The aim of this study was to establish consensus statements on medial patellofemoral ligament (MPFL) reconstruction, anteromedialization tibial tubercle osteotomy, trochleoplasty, and rehabilitation and return to sporting activity in patients with patellar instability, using the modified Delphi process. Methods This was the second part of a s...