Iatrogenic instability of the acromioclavicular joint leads to ongoing impairment of shoulder function even following secondary surgical stabilization.

PURPOSE: Iatrogenic instability of the acromioclavicular joint (ACJ) following distal clavicle excision (DCE) represents an infrequent pathology. Revision surgery to restore ACJ stability and alleviate concomitant pain is challenging due to altered anatomic relationships. The purpose of this study was to evaluate the used salvage techniques and postoperative functional and radiological outcomes in retrospectively identify patients with a painful ACJ following DCE. We hypothesized that iatrogenic instability leads to ongoing impairment of shoulder function despite secondary surgical stabilization. METHODS: 9 patients with a painful ACJ after DCE (6 men, 3 women, 43.3 ± 9.4 years) were followed up at a minimum of 36 months after revision surgery. Besides range of motion (ROM), strength and function were evaluated with validated evaluation tools including the Constant score and the DASH score (Disability of the Arm, Shoulder and Hand questionnaire), specific AC Score (SACS), Nottingham Clavicle Score (NCS), Taft score and Acromioclavicular Joint Instability Score (AJI). Additionally, postoperative X-rays were compared to the unaffected side, measuring the coracoclavicular (CC) and acromioclavicular (AC) distance. RESULTS: At follow-up survey (55.8 ± 18.8 months) all patients but one demonstrated clinical ACJ stability after arthroscopically assisted anatomical ACJ reconstruction with an autologous hamstring graft. Reconstruction techniques were dependent on the direction of instability. The functional results demonstrated moderate shoulder and ACJ scores with a Constant Score of 77.3 ± 15.4, DASH-score of 51.2 ± 23.4, SACS 32.6 ± 23.8, NCS 77.8 ± 14.2, AJI 75 ± 14.7 points and Taft Score 7.6 ± 3.4 points. All patients stated they would undergo the revision surgery again. Mean postoperative CC-distance (8.3 ± 2.8 mm) did not differ significantly from the contralateral side (8.5 ± 1.6 mm) (p > 0,05). However, the mean AC distance was significantly greater with 16.5 ± 5.8 mm compared to the contralateral side (3.5 ± 1.9 mm) (p = 0.012). CONCLUSION: Symptomatic iatrogenic ACJ instability following DCE is rare. Arthroscopically assisted revision surgery with an autologous hamstring graft improved ACJ stability in eight out of nine cases (88.9%). However, the functional scores showed ongoing impairment of shoulder function and a relatively high overall complication rate (33.3%). Therefore, this study underlines the importance of precise preoperative indication and planning and, especially, the preservation of ACJ stability when performing AC joint resection procedures. LEVEL OF EVIDENCE: Case series, LEVEL IV.

Promising clinical and magnetic resonance imaging results after internal bracing of acute posterior cruciate ligament lesions in multiple injured knees.

PURPOSE: The purpose of this study was to evaluate the clinical and radiological outcomes of acute posterior cruciate ligament (PCL) lesions in multiple injured knees that were surgically treated with internal bracing. METHODS: Acute complete PCL lesions in multiple injured knees with subsequent internal-bracing treatment within 21 days between 2014 and 2016 were eligible for inclusion. At final follow-up, patients were assessed with Tegner, Lysholm, and IKDC scores. PCL stability and healing were verified with KT-2000, stress radiography and magnetic resonance imaging (MRI). RESULTS: Fourteen patients [mean age 37.4 (± 17.8; SD) years] were evaluated after a mean follow-up of 19.9 (± 7.7; SD) months. Thirteen patients suffered complete lesions of the PCL with concomitant ligamentous injuries (Schenck I: six cases, Schenck III M: five cases, Schenck IV N: one case, Schenck V: one case). Median Tegner, mean Lysholm and mean IKDC scores at follow-up were 4 (2-7; interquartile range), 69.1 (± 16.6; SD) and 68.9 (± 18.1; SD) respectively. Posterior translation averaged 5.8 (± 2.2; SD) mm with the KT 2000 and stress radiography showed a mean posterior tibial translation of 5.5 (± 4.1; SD) mm in the side to side comparison. MRI showed adequate PCL healing. CONCLUSIONS: Internal bracing as treatment for acute PCL ruptures in multiple injured knees showed adequate restoration of posterior tibial translation in a single-centre study including 14 cases. LEVEL OF EVIDENCE: IV.

Arthroscopic one-step matrix-assisted bone marrow stimulation for the treatment of osteochondral defects of the talus.

OBJECTIVE: All arthroscopic one-step treatment of osteochondral defects of the talus with matrix-assisted bone marrow stimulation with a cell-free hyaluronic acid 3D matrix. INDICATIONS: Symptomatic osteochondral defects of the talus (1-2 cm2, ICRS III-IV). CONTRAINDICATIONS: Large non-shouldered osteochondral defects (2 cm2) of the talus, arthritis, kissing lesions of the distal tibia, metabolic arthropathies, non-reconstructable defects, hindfoot malalignment, chronic inflammatory systemic disorders. SURGICAL TECHNIQUE: Arthroscopic examination of the ankle joint and visualization of the osteochondral defect of the talus to confirm the indication via standard portals. First, debridement of the osteochondral defect with arthroscopic curette or shaver, removal of loose fragments, resection of the sclerotic bone via shaver and measurement of the defect size. Second, multiple perforation of the subchondral plate to recruit mesenchymal stem cells from the underlying bone marrow by an microfracturing awl to stimulate the differentiation of fibrocartilaginous repair tissue in the defect zone. Then, the cell-free hyaluronic acid 3D matrix is placed into the defect via arthroscopic forceps and modulated by a probe to avoid detachment of the matrix by ankle joint movement. POSTOPERATIVE MANAGEMENT: Postoperative management includes movement restrictions for pro- and supination but free passive dorsal extension and plantar flexion. No weight-bearing is allowed for 6 weeks. RESULTS: Twenty-three patients (male: 11/women: 12) with a mean age of 33 years (range: 18-56) and a minimum follow-up of 24 months were included in this retrospective two-center study. The mean values for Foot and Ankle Outcome Score (FAOS) were 79 (range 33-93), for Tegner score 3 (range: 1-5) and the Visual analog scale (VAS) pain 1 (range: 0-3) and VAS function 2 (range: 0-5). At follow-up, MRI was available in 17 of 23 patients. MRI results showed a mean Magnetic Resonance Observation of Cartilage Repair Tissue (MOCART) score of 81 (range: 65-90). Complications were not observed during the follow-up period.