Effectiveness of a home-based re-injury prevention program on motor control, return to sport and recurrence rates after anterior cruciate ligament reconstruction: study protocol for a multicenter, single-blind, randomized controlled trial (PReP)

Background: Although anterior cruciate ligament (ACL) tear-prevention programs may be effective in the (secondary) prevention of a subsequent ACL injury, little is known, yet, on their effectiveness and feasibility. This study assesses the effects and implementation capacity of a secondary preventive motor-control training (the Stop-X program) after ACL reconstruction. Methods and design: A multicenter, single-blind, randomized controlled, prospective, superiority, two-arm design is adopted. Subsequent patients (18–35 years) with primary arthroscopic unilateral ACL reconstruction with autologous hamstring graft are enrolled. Postoperative guideline rehabilitation plus Classic follow-up treatment and guideline rehabilitation plus the Stop-X intervention will be compared. The onset of the Stop-X program as part of the postoperative follow-up treatment is individualized and function based. The participants must be released for the training components. The endpoint is the unrestricted return to sport (RTS) decision. Before (where applicable) reconstruction and after the clearance for the intervention (aimed at 4–8 months post surgery) until the unrestricted RTS decision (but at least until 12 months post surgery), all outcomes will be assessed once a month. Each participant is consequently measured at least five times to a maximum of 12 times. Twelve, 18 and 24 months after the surgery, follow-up-measurements and recurrence monitoring will follow. The primary outcome assessement (normalized knee-separation distance at the Drop Jump Screening Test (DJST)) is followed by the functional secondary outcomes assessements. The latter consist of quality assessments during simple (combined) balance side, balance front and single-leg hops for distance. All hop/jump tests are self-administered and filmed from the frontal view (3-m distance). All videos are transferred using safe big content transfer and subsequently (and blinded) expertly video-rated. Secondary outcomes are questionnaires on patient-reported knee function, kinesiophobia, RTS after ACL injury and training/therapy volume (frequency – intensity – type and time). All questionnaires are completed online using the participants’ pseudonym only. Group allocation is executed randomly. The training intervention (Stop-X arm) consists of self-administered home-based exercises. The exercises are step-wise graduated and follow wound healing and functional restoration criteria. The training frequency for both arms is scheduled to be three times per week, each time for a 30 min duration. The program follows current (secondary) prevention guidelines. Repeated measurements gain-score analyses using analyses of (co-)variance are performed for all outcomes. Trial registration: German Clinical Trials Register, identification number DRKS00015313. Registered on 1 October 2018

Clinical and radiographic results of cementless total knee arthroplasty with the LCS prothesis

Die LCS Prothese wurde 1977 von Buechel und Pappas entwickelt und gilt als Vorreiter der Mobile-bearing Knieendoprothesen, seither erfuhr diese eine kontinuierliche Weiterentwicklung. Bei Verwendung des anterior/posterior Gleitlagers (APG) bleibt das hintere Kreuzband erhalten, bei der Rotationsplattform (RP) wird dieses entfernt. Ziel der vorliegenden Arbeit war es, die Ergebnisse nach zementfreiem Kniegelenksoberflächenersatz Typ LCS mit mobilem Gleitlager; Rotationsplattform (RP) vs. anterior/posterior Gleitlager (APG) zu vergleichen. Methodik: Im Zeitraum von 01/05 bis 12/06 wurden in unserer Klinik 60 Patienten mit einer zementfreien Knieendoprothese, Typ LCS Complete (DePuy), bei primärer Gonarthrose versorgt. Als mobile-bearing Gleitlager wurde in 33 Fällen das RP-Lager, in 27 Fällen das APG-Lager gewählt. Alle Patienten wurden klinisch und radiologisch untersucht und die Ergebnisse nach dem Knee Society Scoring System (KSS), dem Hospital for Special Surgery Score (HSS) und dem krankheitsspezifischen Knee Injury and Osteoarthritis Outcome Score (KOOS) ausgewertet. Die radiologische Auswertung erfolgte nach Kriterien des Roentgenographic Evaluation System der Knee Society (KRESS). Ergebnisse: Der mittlere Nachuntersuchungszeitraum betrug für das RP-Lager 33±5 Monate für das APG-Lager 34±5 Monate. Der KSS lag bei 88±13 (RP) und bei 90±10 (APG) Punkten (p= 0.85). Der HSS lag bei 87,2±10,8 (RP) und bei 88±10 (APG). Der KOOS Score zeigte keinen signifikanten Unterschied der beiden Gleitlager. Röntgenologisch zeigte sich ein totaler Valguswinkel von 185,3° (RP) und 185,6° (APG). Insgesamt konnten in der RP Gruppe 18 und in der APG Gruppe 13 Lysesäume gemessen werden, welche hauptsächlich bei 1mm lagen und ohne klinische Relevanz waren. Es zeigte sich kein signifikanter Unterschied der beiden Untersuchungsgruppen. In 6,7% der Fälle zeigten sich postoperativ Komplikationen, der Anteil an Reoperationen betrug 5% des Gesamtkollektives ohne signifikanten Unterschied. Schlussfolgerung: Die Auswertung der klinischen sowie radiologischen Ergebnisse zeigte keinen signifikanten Unterschied der beiden verwendeten mobile-bearing Gleitlager und entsprach den Ergebnissen anderer Autoren. Aufgrund des kurzen Nachuntersuchungszeitraumes ist insbesondere für die radiologische Auswertung eine Studie mit längerem Beobachtungszeitraum notwendig. Zusammenfassend besteht kein signifikanter Unterschied in den klinischen und radiologischen Ergebnissen.The Low Contact Stress mobile- bearing knee prothesis was developed in 1977 by Buechel and Pappas. Today, the LCS knee, unchanged in almost 35 years, remains a relevant and important design concept. Using the anterior-posterior-glide prosthesis, the posterior cruciate ligament was preserved. Knees that were treated with the rotating-platform LCS, the posterior cruciate ligament was sacrificed. The purpose of the study was to compare the results of these two types of mobile-bearing knee replacement. Methods: 60 patients with primary osteoarthritis underwent cementless total knee replacement. In 33 cases the rotation-platform and in 27 cases the anterior-posterior mobile-bearing inlay was used. All patients were clinically and radiographically analyzed. Clinical evaluation was performed using the KSS, the HSS and the KOOS Scoring system. Radiographic evaluation was done according to the knee roentgenopgraphic scoring system. Results: The mean duration of follow-up was 33±5 month (rotation-platform) and 34±5 month (anterior-posterior glide) on average. The mean knee Score was 88±13 (rotation-platform) and 90±10 (anterior-posterior glide) points (p= 0.85). The Hospital for Special Surgery Score was 87,2±10,8 points for the knees treated with the rotation-platform prosthesis and 88±10 points for those treated with the anterior-posterior prosthesis. KOOS Score was not significant different between both study groups. Radiolucent lines were small, not progressive and not significant different between rotation- platform and anterior-posterior mobile-bearing prosthesis. Complications occurred in 6,7 %, 5% required revision surgery with no significant difference between both study groups. Conclusion: The results of both types of mobile- bearing prothesis are comparable with regard to clinical and radiographic examination. No significant difference was found. With regard to the clinical relevance studies with long-term follow-up and evaluation of more patients is needed

Anterior cruciate ligament autograft maturation on sequential postoperative MRI is not correlated with clinical outcome and anterior knee stability

Purpose!#!Magnetic resonance imaging (MRI) signal intensity is correlated to structural postoperative changes of the anterior cruciate ligament (ACL) autograft. The purpose of this study was to investigate the ACL autograft maturation process via MRI over 2 years postoperatively, compare it to a native ACL signal and correlate the results with clinical outcome, return to preinjury sports levels, and knee laxity measurements.!##!Methods!#!ACL autograft signal intensity was measured in 17 male patients (age, 28.3 ± 7.0 years) who underwent ACL reconstruction with hamstring autograft at 6 weeks, 3-, 6-, 12-, and 24 months postoperatively by 3 Tesla MRI. Controls with an intact ACL served as control group (22 males, 8 females; age, 26.7 ± 6.8 years). An ACL/PCL ratio (APR) and ACL/muscle ratio (AMR) was calculated to normalize signals to soft tissue signal. APR and AMR were compared across time and to native ACL signal. Clinical outcome scores (IKDC, Lysholm), return to preinjury sports levels (Tegner activity scale), and knee laxity measurement (KT-1000) were obtained and correlated to APR and AMR at the respective time points.!##!Results!#!The APR and AMR of the ACL graft changed significantly from the lowest values at 6 weeks to reach the highest intensity after 6 months (p < 0.001). Then, the APR and AMR were significantly different from a native ACL 6 months after surgery (p < 0.01) but approached the APR and AMR of the native ACL at 1- and 2 years after surgery (p < 0.05). The APR changed significantly during the first 2 years postoperatively in the proximal (p < 0.001), mid-substance (p < 0.001), and distal (p < 0.01) intraarticular portion of the ACL autograft. A hypo-intense ACL MRI signal was associated with return to the preinjury sports level (p < 0.05). No correlation was found between ACL MRI graft signal and clinical outcome scores or KT-1000 measurements.!##!Conclusion!#!ACL grafts undergo a continuous maturation process in the first 2 years after surgery. The ACL graft signals became hyper-intense 6 months postoperatively and approximated the signal of a native intact ACL at 12- and 24 months. Patients with a hypo-intense ACL graft signal at 2 years follow-up were more likely to return to preinjury sports levels. The results of the present study provide a template for monitoring the normal ACL maturation process via MRI in case of prolonged clinical symptoms. However, subjective outcome and clinical examination of knee laxity remain important to assess the treatment success and to allow to return to sports.!##!Level of evidence!#!III

Outcomes after bone grafting in patients with and without ACL revision surgery: a retrospective study

Abstract Background Current literature is lacking of data regarding functional outcomes in patients following bone tunnel grafting with or without revision anterior cruciate ligament (ACL) reconstruction. Therefore, the aim of the present study was to evaluate the clinical outcome in patients with (RACL) or without revision ACL reconstruction (OBG) following bone grafting. Methods Fifty-nine patients (18 female, 41 male) who underwent bone grafting due to recurrent, symptomatic ACL deficiency following ACL reconstruction between 2011 and 2014 were retrospectively analyzed. In 44 patients (mean age: 30,5 ± 8,5 years) a staged revision ACL reconstruction (RACL) was performed after bone grafting. 10 patients (mean age: 33.2 ± 10.3 years) refused to have ACL revision surgery after bone grafting (OBG). Outcome measures included instrumented laxity testing, the International Knee Documentation Committee (IKDC) score, the Knee Injury and Osteoarthritis Outcome Score (KOOS), Lysholm score and Tegner activity scale. Results After mean period of 33,9 ± 17.0 months, 54 patients were available for follow up examination. In the RACL group, the Lysholm score was 77,2 ± 15,5 (range 35–100), the mean IKDC subjective knee score was 69,0 ± 13,4 (range 39,1–97,7) and the mean Tegner activity score was 4,1 ± 1,5 (range, 1–9). Similarly, in the OBG group the mean Lysholm score was 72,90 ± 18,7 (range 50–100), the mean IKDC subjective score was 69,3 ± 20,0 (range 44,1–100) and the mean Tegner activity score was 4,6 ± 1,2 (range, 3–6). No significant difference was observed between the two groups. Knee laxity measurements were elevated without revision ACL surgery, however the difference was not significant. Conclusion Bone tunnel grafting with or without second stage ACL revision surgery showed no significant difference in functional outcome score. Thus, in case of revision ACL instability careful patient selection is necessary and expectations should be discussed openly with the patients

Biceps Brachii Alterations Following the Latarjet Procedure: A Prospective Multicenter Study

Purpose: To prospectively investigate the postoperative forearm supination and elbow flexion strength of both upper extremities and popeye deformity in patients who underwent a mini-open Latarjet procedure for anterior shoulder instability. Methods: Patients who underwent a mini-open Latarjet procedure at two specialized shoulder centers were prospectively evaluated preoperatively (T0) and at least 6 months (T1) after surgery. Subjects were tested for elbow flexion and forearm supination strength of both upper extremities using an isometric dynamometer and customized torque dynamometer. Clinical outcome was assessed by the Constant Score (CS), American Shoulder and Elbow Score (ASES) and Simple Shoulder test (SST). Popeye deformity was defined as a distalization of the greatest circumference of the biceps muscle belly towards the lateral epicondyle of the elbow. Results: A total of 20 patients with a mean age of 27 ± 6 years were included in the study. At a mean follow-up of 10 ± 3 months, the elbow flexion strength was restored to the preoperative state (p = 0.240). Forearm supination strength significantly decreased at final follow-up, to 88 % in the surgical arm (p = 0.015) vs. 90 % in the non-surgical arm (p = 0.023). There was no statistical difference when comparing both arms concerning elbow flexion strength (p = 0.510) and forearm supination strength (p = 0.495). No significant popeye deformity was observed in both arms (p = 0.111 vs. p = 0.508). Clinical outcome scores improved significantly from 73 ± 18 to 82 ± 13 (p = 0.014) for CS and 76 ± 22 to 89 ± 12 (p = 0.008) for ASES score preoperatively to final follow-up. No difference in the SST was documented (p = 0.10). Conclusion: The Latarjet procedure showed to preserve elbow flexion strength and provided comparable forearm supination strength compared to the uninjured arm with reliable clinical outcome in this study population. However, a decrease of forearm supination strength in both arms was persistent at a mean of 10 months postoperatively. No popeye deformity was noted in the postoperative examinations. Level of evidence: Case series, Level III

Effect of Lower Limb Alignment in Medial Meniscus–Deficient Knees on Tibiofemoral Contact Pressure

Background: Degenerative medial meniscal tears and subsequent partial meniscal resection compromise meniscal function and lead to an overload of the medial compartment. In addition, lower limb alignment plays a key role in load distribution between the medial and lateral knee compartments, and varus alignment is a potential risk factor for medial osteoarthritis. Purpose/Hypothesis: The purpose of this biomechanical study was to investigate the effect of valgus and varus alignment on peak pressure and contact area in knees with concomitant horizontal medial meniscal tears and subsequent leaflet resection. It was hypothesized that varus alignment in combination with meniscal loss leads to the highest peak pressure within the medial compartment. Study Design: Controlled laboratory study. Methods: Six fresh-frozen human cadaveric knees were axially loaded using a 1000-N compressive load in full extension with the mechanical axis rotated to intersect the tibial plateau at 40%, 45%, 50%, 55%, and 60% of its width (TPW) to simulate varus and valgus alignment. Tibiofemoral peak contact pressure and contact area of the medial and lateral compartments were determined using pressure-sensitive foils in each of 4 different meniscal conditions: intact, 15-mm horizontal tear of the posterior horn, inferior leaflet resection, and resection of both leaflets. Results: The effect of alignment on peak pressure (normalized to the neutral axis) within the medial compartment in cases of an intact meniscus was measured as follows: varus shift resulted in a mean increase in peak pressure of 18.5% at 45% of the TPW and 37.4% at 40% of the TPW, whereas valgus shift led to a mean decrease in peak pressure of 8.7% at 55% of the TPW and 23.1% at 60% of the TPW. Peak pressure changes between the intact meniscus and resection within the medial compartment was less in valgus-aligned knees (0.21 MPa at 60% TPW, 0.59 MPa at 50% TPW, and 0.76 MPa at 40% TPW). Contact area was significantly reduced after partial meniscal resection in the neutral axis (intact, 553.5 +/- 87.6 mm(2); resection of both leaflets, 323.3 +/- 84.2 mm(2); P < .001). This finding was consistent in any alignment. Conclusion: Both partial medial meniscal resection and varus alignment led to an increase in medial compartment peak pressure. Valgus alignment prevented medial overloading by decreasing contact pressure even after partial meniscal resection. A horizontal meniscal tear did not influence peak pressure and contact area even in varus alignmen

Ultrasound-based examination of the medial ligament complex shows gender- and age-related differences in laxity

Purpose!#!Ultrasound (US) examination of the medial joint space of the knee has played a subordinate diagnostic role up till now. The purpose of the present study was to describe mean values of medial joint width and to investigate the impact of gender, age, and body mass index (BMI) on medial joint laxity in healthy knees using modern, dynamic US in a standardized fashion in unloaded and standardized loaded conditions.!##!Methods!#!A total of 65 subjects with 79 healthy knees were enrolled in this study. All volunteers underwent clinical examination of the knee. The medial knee joint width was determined using US in a supine position at 0° and 30° of knee flexion in unloaded and standardized loaded (= 15 Dekanewton, daN) conditions using a specific device. Mean values were described and correlations between medial knee joint width and gender, age, and BMI were assessed.!##!Results!#!Thirty-two females and 33 males were enrolled in this study. The mean medial joint width in 0° unloaded was 5.7 ± 1.2 mm and 7.4 ± 1.4 mm loaded. In 30° of knee flexion, the mean medial joint width was 6.1 ± 1.1 mm unloaded and 7.8 ± 1.2 mm loaded. The average change between unloaded and loaded conditions in 0° was 1.7 ± 1.0 mm and in 30° 1.7 ± 0.9 mm. A significant difference between genders was evident for medial joint width in 0° and 30° of flexion in unloaded and loaded conditions (p &amp;lt; 0.05). With rising age, a significant increased change of medial joint space width between unloaded and loaded conditions could be demonstrated in 0° (p = 0.032). No significant correlation between BMI and medial joint width in US could be found.!##!Conclusion!#!Mean values of medial joint width in unloaded and standardized loaded conditions using a fixation device could be demonstrated. Based on the results of this study, medial knee joint width in US is gender- and age-related in healthy knees. These present data may be useful for evaluating patients with acute or chronic pathologies to the medial side of the knee.!##!Level of evidence!#!III

Ultrasound-based evaluation revealed reliable postoperative knee stability after combined acute ACL and MCL injuries

Purpose!#!Anterior cruciate ligament (ACL) injuries are often combined with lesions of the medial collateral ligament (MCL). The aim of this study was to evaluate treatment outcome of combined acute ACL and MCL lesions using functional US and clinical examination.!##!Methods!#!Patients aged &amp;gt; 18 years undergoing primary ACL reconstruction with concomitant operative (group 1) or non-operative treatment of the MCL (group 2) between 2014 and 2019 were included after a minimum follow-up of 12 months. Grade II MCL injuries with dislocated tibial or femoral avulsions and grade III MCL ruptures underwent ligament repair whereas grade II injuries without dislocated avulsions were treated non-operatively. Radiological outcome was assessed with functional US examinations. Medial knee joint width was determined in a supine position at 0° and 30° of knee flexion in unloaded and standardized loaded (= 15 Dekanewton) conditions using a fixation device. Clinical examination was performed and patient-reported outcomes were assessed by the use of the subjective knee form (IKDC), Lysholm score, and the Tegner activity scale.!##!Results!#!A total of 40 patients (20 per group) met inclusion criteria. Mean age of group 1 was 40 ± 12 years (60% female) with a mean follow-up of 33 ± 17 months. Group 2 showed a mean age of 33 ± 8 years (20% female) with a mean follow-up of 34 ± 15 months. Side-to-side differences in US examinations were 0.4 ± 1.5 mm (mm) in 0° and 0.4 ± 1.5 mm in 30° knee flexion in group 1, and 0.9 ± 1.1 mm in 0° and 0.5 ± 1.4 mm in 30° knee flexion in group 2, with no statistically significant differences between both groups. MCL repair resulted in lower Lysholm scores (75 ± 19 versus 86 ± 15; p &amp;lt; 0.05). No significant differences could be found for subjective IKDC or Tegner activity scores among the two groups.!##!Conclusion!#!A differentiated treatment concept in combined ACL and MCL injuries based on injury patterns leads to reliable postoperative ligamentous knee stability in US-based and clinical examinations. However, grade II and III MCL lesions with subsequent operative MCL repair (group 1) result in slightly poorer subjective outcome scores.!##!Level of evidence!#!Retrospective cohort study; Level III