Methods of operative fixation of the acromio-clavicular joint: a biomechanical comparison

PURPOSE: Three different methods of fixation used in acute disruption of the acromio-clavicular (AC) joint-namely, the coraco-clavicular Bosworth screw (CC Screw), a coraco-clavicular sling of Mersilene #5 tape (CC Sling), and a Hook Plate-were compared to baseline to see which could most closely replicate the stiffness of healthy cadaveric AC specimens (Intact). HYPOTHESIS: It is hypothesized that the Hook Plate method, as compared with the other reconstructions tested, will be most similar mechanically to the intact AC joint with respect to present outcome measures. METHODS: Five matched pairs of fresh-frozen cadaveric specimens were tested. Stiffness was tested with superior cyclic loads to 70 N. The stiffness for each specimen was initially tested with all the ligaments in place (Intact). The AC and CC ligaments were then sectioned, and stiffness was tested, in varying order, with reconstructions using the CC Screw, the CC Sling, and the Hook Plate. Failure testing consisted of taking either the CC Screw or Hook Plate to failure within each matched pair. RESULTS: The CC Screw and the CC Sling, respectively, showed stiffnesses of 46 +/- 23 N/mm and 15 +/- 8 N/mm, which was significantly different from the Intact specimen (P < 0.05). The Hook Plate had a stiffness of 26 +/- 17 N/mm, most comparable to the Intact joint stiffness of 25 +/- 8 N/mm (P = 0.785). With failure testing, the CC Screw failed at a significantly higher load than the Hook Plate (744 +/- 184 N vs 459 +/- 188 N) (P = 0.034). CONCLUSION: The CC Screw demonstrated the greatest stiffness with repetitive loading to 70 N. The Hook Plate had a stiffness most similar to the normal physiologic state of the AC joint. The CC Sling was significantly less stiff than the Intact joint or the other methods of fixation. SIGNIFICANCE: Although the stiffest construct is the CC Screw, Hook Plate fixation allows physiologic motion without pathological deformation and most closely resembles the stiffness of the native AC joint for the current test procedure used.     

Combination of Clavicular Hook Plate with Coracoacromial Ligament Transposition in Treatment of Acromioclavicular Joint Dislocation

ObjectiveTo evaluate the clinical efficacy of Arbeitsgemeinschaft für Osteosynthesefragen (AO) clavicular hook plate (CHP) combined with coracoacromial ligament transposition for Rockwood III‐V dislocation of AC joint, providing an alternative choice for AC joint dislocation treatment.MethodsTwenty‐five patients diagnosed with Rockwood III‐V dislocation of acromioclavicular (AC) joint, including 18 males and seven females, aged 43.5 ± 2.4 years old on average, who had undergone open reduction and AO CHP in combination with coracoacromial (CC) ligament transposition between January 2010 and December 2015, were retrospectively analyzed. Among them, 17 cases were diagnosed as type III, five cases were type IV, and three cases were type V. The surgery mainly included three main steps: bone flap incision, drilling in the clavicle, and hook plate fixation and AC joint reposition. The treatment efficacy was evaluated through clinical examinations and imaging studies for the shoulder joint, including gross observation and measuring coracoid clavicle distance (CC‐Dist) using orthophoria X‐ray before and 1 year after the surgery, and University of California (UCLA) shoulder rating scale.ResultsAll the patients were followed up three to four times in 18 months (12–24 months) on average, and the UCLA rating results showed that there were 17 excellent cases (68%), five good cases (20%), and three fair cases (12%). The CC‐Dist values after the surgery reduced to 9.7 ± 0.7 mm, which was significantly (P < 0.05) lower compared to that before the surgery (15.8 ± 1.6 mm). Most (88%) of the cases showed almost normal joint function and good anatomical arrangement of the acromioclavicular joint, without any secondary dislocation, and for them, 12 ± 2 weeks on average were needed to regain the normal function of shoulder joint movement.ConclusionDue to the stable fixation, fewer complications, and satisfactory therapeutic effect with great clinical value, the combination of AO CHP and CC ligament transposition is expected to be used for treating Rockwood III‐V dislocation of AC joint.     

关节镜下四袢与双袢固定修复急性肩锁关节Rockwood V型脱位疗效对比研究

目的对比评估双骨道四袢与单骨道双袢固定修复急性肩锁关节Rockwood Ⅴ型脱位疗效。 方法回顾性分析2010年5月至2016年5月于深圳大学第一附属医院接受关节镜下双骨道四袢与单骨道双袢固定修复急性肩锁关节Rockwood Ⅴ型脱位的所有患者,其中入选82例手术患者,四袢双骨道组与双袢单骨道组各41例。术后2年内随访观察患者的视觉模拟评分（visual analogue scale,VAS） 、患者恢复运动时间、恢复运动患者数量、Constant功能评分、Karlsson肩锁关节功能评分,并通过影像学观察评估喙锁关节和肩锁关节的间隙。 结果术后2年内末次随访X线片显示四袢双骨道组患侧平均喙锁关节和肩锁关节的间隙与双袢单骨道组对比明显减小,且差异具有统计学意义（P<0.05）;双袢单骨道组患者健侧平均喙锁关节和肩锁关节的间隙与患侧对比明显减小,且差异具有统计学意义（P<0.05）;然而四袢双骨道组患者健侧平均喙锁关节和肩锁关节的间隙与患侧对比差异无统计学意义（P>0.05）。两组患者术后末次随访患肢疼痛均有明显减轻,术前与术后VAS评分对比差异具有统计学意义,两组组间对比差异无统计学意义。四袢双骨道组重返运动的时间较双袢单骨道组明显缩短,重返患者数目明显多于双袢单骨道组,且Constant功能评分、Karlsson肩锁关节功能评分均明显优于双袢单骨道组,差异均具有统计学意义（P<0.05）。四袢双骨道组并发症明显少于双袢单骨道组。 结论采用关节镜下双骨道四袢固定治疗Rockwood V型脱位,方法固定可靠,并发症少,较双袢单骨道固定效果更佳,是治疗急性肩锁关节Rockwood V型脱位损伤较好的方法。     

新型胸锁钩钢板治疗胸锁关节周围不稳定性骨折脱位的疗效观察

目的:探讨新型胸锁钩钢板治疗胸锁关节周围不稳定性骨折脱位的临床疗效。方法 :自2011年6月至2013年12月,应用胸锁钩钢板对32例成年胸锁关节骨折脱位患者进行手术治疗。其中男24例,女8例;年龄25~76岁,平均42岁;胸锁关节前脱位12例,胸锁关节后脱位5例,锁骨内侧端骨折10例,骨折合并脱位5例。胸锁关节前骨折脱位采用标准胸锁钩钢板,后脱位则在钢板钩的远端,即胸骨柄前方加用螺母和垫片,预防术后再脱位。根据Rockwood评分法评定疗效。结果 :患者手术过程中无并发症发生。术后复查X线片及CT显示胸锁关节解剖位置正常,内固定位置良好。32例均获得随访,时间6~24个月,平均10个月。术后3~6个月骨折达Ⅰ期愈合,胸锁关节无再脱位,锁骨内侧端解剖结构均恢复,功能满意,其中9例患者胸锁关节周围存在肿胀,但无疼痛等症状。Rockwood评分结果12.78±1.43;疗效优24例,良8例。结论:使用该新型胸锁钩钢板治疗胸锁关节周围不稳定性骨折,内植物固定确实可靠,安全性高,操作简便,为治疗此类创伤提供了一种可靠的方法。     

Instabilitätsmuster bei Akromioklavikulargelenkverletzungen vom Typ Rockwood III

Background

There is no evidence-based treatment algorithm established for acromioclavicular joint (AC joint) dislocation classified as type Rockwood III injury. Recent meta-analyses revealed no advantage of surgical treatment compared to the non-operative approach. Both surgical and non-surgical approaches have been reported with inconsistent results. Therefore, the hypothesis of the current study was that patients classified as having Rockwood grade III injury may have different degrees of horizontal AC joint instability.

Material and methods

A total of 18 consecutive patients who had sustained a dislocation of the AC joint classified as Rockwood III were evaluated radiologically to quantify the horizontal instability of the AC joint. The specific radiological investigation included lateral stress x-rays (Alexander view) und axial stress x-rays with the affected arm in a horizontal adduction position.

Results

The dynamic horizontal instability of the AC joint was found to be independent of the vertical dislocation measured in the Rockwood classification.

Conclusion

For further treatment studies Rockwood III injuries should be distinguished in patients presenting with or without a substantial horizontal AC joint instability.     

Acromioclavicular stability: a biomechanical comparison of acromioplasty to acromioplasty with coplaning of the distal clavicle

Purpose: The purpose of the study was to compare the laxity of the acromioclavicular (AC) joint in the superior, posterior, and anterior planes after isolated acromioplasty and after acromioplasty with inferior clavicular coplaning. Type of Study: In vitro (cadaveric) analysis. Methods: Eight fresh-frozen cadaveric shoulders were evaluated using a hydraulic actuator. While the scapula was stabilized, a 30-N force was applied to the distal clavicle perpendicular to the AC joint in the superoinferior plane and parallel to the joint in the anteroposterior plane. Laxity of the AC joint in the superior, anterior, and posterior directions was evaluated via load-displacement analysis after acromioplasty and after acromioplasty with coplaning. Results: Coplaning the distal clavicle increased superior AC laxity by 53% compared with acromioplasty alone (P = .012). With regard to anteroposterior laxity, coplaning increased anterior translation by 19% (P = .047) and increased posterior translation by 16% (P = .237). Bony impingement was seen to limit posterior translation in 3 specimens. Conclusions: Acromioplasty with coplaning increases AC laxity significantly in the superior and anterior directions as compared with acromioplasty alone. A trend toward increased posterior translation was found; posterior bony impingement may limit posterior laxity.     

The use of hook plate in type III and V acromio-clavicular Rockwood dislocations: clinical and radiological midterm results and MRI evaluation in 42 patients

BackgroundAcromio-clavicular (AC) joint dislocations are very common following falls on the shoulder or an overstretched hand. The best treatment for such lesions remains a matter of debate. Several studies have, however, lent support to the surgical role of the hook plate in Rockwood type III and V AC dislocations. The aim of this study was to evaluate the midterm clinical results and magnetic resonance imaging (MRI) features of coraco-clavicular ligaments 18 months after an AC dislocation treated with an AC Dreithaler hook plate.Patients and methodsThe cohort was made up of a consecutive series of 42 patients, who underwent surgery between November 2002 and December 2006 for an AC dislocation. They were classified, according to the Rockwood classification, as 22 grade III and 20 grade V dislocations. Surgical treatment consisted of open reduction and stabilisation with an AC Dreithaler hook plate. A clinical and radiological follow-up examination was performed 1 and 3 months after surgery, that is, before removal of the plate, and 12 months following removal.Eighteen months after the trauma, an MRI and a clinical examination were performed and the Constant–Murley scores calculated.ResultsAn acceptable joint alignment was achieved in all the patients after surgery; 1 year after plate removal, five cases (12%) of dislocation recurrence were reported. MRI showed the coraco-clavicular ligaments had healed in the remaining 37 cases (88%).ConclusionAn AC plate is a useful technique in acromio-clavicular dislocations because it is easy to implant, requires mini-invasive access and results in early resumption of normal activity. MRI can be used to evaluate healing of coraco-clavicular ligaments. A long-term follow-up study is, however, warranted to assess the likelihood of recurrence.Level of evidenceLevel IV, therapeutic cases series.     

The Munich Shoulder Questionnaire (MSQ): development and validation of an effective patient-reported tool for outcome measurement and patient safety in shoulder surgery

Purpose

In this retrospective study we investigated the clinical and radiological outcome after operative treatment of acute Rockwood III-V injuries of the AC-joint using two acromioclavicular (AC) cerclages and one coracoclavicular (CC) cerclage with resorbable sutures.

Methods

Between 2007 and 2009 a total of 39 patients fit the inclusion criteria after operative treatment of acute AC joint dislocation. All patients underwent open reduction and anatomic reconstruction of the AC and CC-ligaments using PDS? sutures (Polydioxane, Ethicon, Norderstedt, Germany). Thirty-three patients could be investigated at a mean follow up of 32±9?months (range 24?C56?months).

Results

The mean Constant score was 94.3±7.1 (range 73?C100) with an age and gender correlated score of 104.2%±6.9 (88-123%). The DASH score (mean 3.46±6.6 points), the ASES score (94.6±9.7points) and the Visual Analogue Scale (mean 0.5±0,6) revealed a good to excellent clinical outcome. The difference in the coracoclavicular distance compared to the contralateral side was <5?mm for 28 patients, between 5-10?mm for 4 patients, and more than 10?mm for another patient. In the axial view, the anterior border of the clavicle was within 1?cm (ventral-dorsal direction) of the anterior rim of the acromion in 28 patients (85%). Re-dislocations occured in three patients (9%).

Conclusion

Open AC joint reconstruction using AC and CC PDS cerclages provides good to excellent clinical results in the majority of cases. However, radiographically, the CC distance increased significantly at final follow up, but neither the amount of re-dislocation nor calcifications of the CC ligaments or osteoarthritis of the AC joint had significant influence on the outcome.

Level of evidence

Case series, Level IV     

Comparison of Results between Hook Plate Fixation and Ligament Reconstruction for Acute Unstable Acromioclavicular Joint Dislocation

BackgroundIn the present study, we aimed to compare clinical and radiographic outcomes between hook plate fixation and coracoclavicular (CC) ligament reconstruction for the treatment of acute unstable acromioclavicular (AC) joint dislocation.MethodsForty-two patients who underwent surgery for an unstable acute dislocation of the AC joint were included. We divided them into two groups according to the treatment modality: internal fixation with a hook plate (group I, 24 cases) or CC ligament reconstruction (group II, 18 cases). We evaluated the clinical outcomes using a visual analog scale (VAS) for pain and Constant-Murley score, and assessed the radiographic outcomes based on the reduction and loss of CC distance on preoperative, postoperative, and final follow-up plain radiographs.ResultsThe mean VAS scores at the final follow-up were 1.6 ± 1.5 and 1.3 ± 1.3 in groups I and II, respectively, which were not significantly different. The mean Constant-Murley scores were 90.2 ± 9.9 and 89.2 ± 3.5 in groups I and II, respectively, which were also not significantly different. The AC joints were well reduced in both groups, whereas CC distance improved from a mean of 215.7% ± 50.9% preoperatively to 106.1% ± 10.2% at the final follow-up in group I, and from 239.9% ± 59.2% preoperatively to 133.6% ± 36.7% at the final follow-up in group II. The improvement in group I was significantly superior to that in group II (p < 0.001). Furthermore, subluxation was not observed in any case in group I, but was noted in six cases (33%) in group II. Erosions of the acromion undersurface were observed in 9 cases in group I.ConclusionsIn cases of acute unstable AC joint dislocation, hook plate fixation and CC ligament reconstruction yield comparable satisfactory clinical outcomes. However, radiographic outcomes based on the maintenance of reduction indicate that hook plate fixation is a better treatment option.     

The Tight-Rope Technique versus Clavicular Hook Plate for Treatment of Acute Acromioclavicular Joint Dislocation: A Systematic Review and Meta-Analysis

Abstract

Objective: The efficacy of the tight-rope (TR) technique and clavicular hook plate (CHP) for the treatment of acute acromioclavicular (AC) joint dislocation is controversial. This meta-analysis aimed to evaluate which method is more appropriate for the treatment of acute AC joint dislocation. Methods: We systematically searched the PubMed, EMBASE, Scopus, ISI Web of Science, Chinese VIP Database, and Chinese Wan-Fang databases from inception to January 2018 using the search term “acromioclavicular joint dislocation AND hook plate.” All prospective and retrospective controlled trials that had compared functional scores, pain scores, reduction loss rates, coracoclavicular (CC) distances, and complications between TR and CHP for acute AC joint dislocation were identified. A total of 13 of 587 studies with 732 patients were included. TR was preferential to CHP for AC joint dislocation given its higher Constant–Murley score, lower Visual Analog Scale pain score, and comparable reduction loss rate and CC distance. Subgroup analyses of the surgical type of TR did not affect the outcome. Results: The TR technique appears to be associated with better functional recovery and less pain than CHP. In addition, it does not increase the risk of reduction loss, CC distance, or operation time. It is also not associated with other complications except the implant migration, and does not require removal of the internal fixation. Conclusions: Thus, our results indicated that for AC joint dislocation, the TR technique may be preferential.     

Evaluation of coracoclavicular stabilization of acute acromioclavicular joint dislocation with multistrand titanium cables

Purpose

The aim of this study was to evaluate the outcome of surgical treatment of acute acromioclavicular (AC) joint dislocation with multistrand titanium cables for coracoclavicular (CC) stabilization.

Methods

Forty-two patients with acute AC joint dislocation, including Rockwood type III 14 cases, type IV 2 cases and type V 26 cases, were operated with CC stabilization using multistrand titanium cables. The cables were removed 3–12 months after surgery. The function outcome was evaluated by Constant scores and visual analog scale (VAS) scores. Radiological examination included bilateral antero-posterior and axillary radiography.

Results

Three patients were lost to follow-up. Thirty-nine patients had an average follow-up time of 42 months (range 34–60). The Constant scores were 95.3 ± 9.3 at final evaluation. Preoperative and final follow-up VAS scores were 5.6 ± 1.5 and 0.4 ± 1.2, respectively (P < 0.05). Radiographs showed anatomical reduction in 32 patients. Cables breakage occurred in two patients.

Conclusions

CC stabilization with multistrand titanium cables was an effective and safe alternative to other procedures for the treatment of acute high-grade AC joint dislocations. It can provide immediate joint stabilization and allow early mobilization of limb with satisfied functional recovery.     

胸锁钩钢板治疗胸锁关节脱位的临床观察

目的:观察应用胸锁钩钢板治疗胸锁关节脱位患者的临床治疗效果。方法:2010年6月至2012年6月对7例胸锁关节脱位患者行胸锁钩钢板复位固定术治疗,其中男5例,女2例;年龄38～54岁,平均42.3岁;病程1～4周。术前患者均有外伤史,患侧胸锁关节肿胀、疼痛明显,患侧肩关节活动明显受限。术前X线片及CT证实为胸锁关节脱位,根据Rockwood评分法对术后疗效进行评价。结果:本组7例胸锁关节脱位患者按Rockwood评分法进行评价,优6例,良1例。术后未出现内固定松动、断裂,未出现再次脱位,肩关节功能良好,胸锁关节无疼痛,外观无畸形,患肢活动自如无疼痛。结论:胸锁钩钢板治疗胸锁关节脱位,手术操作简单,固定可靠,疗效肯定,值得临床推广。     

Surgical reconstruction of the acromioclavicular joint: Can we identify the optimal approach?

Injuries to the acromioclavicular (AC) joint are common, tending to occur secondary to traumatic injuries. Rockwood grade IV, V and VI injuries involve complete dislocation of the joint and require surgical reconstruction, with inconclusive literature on whether grade III injuries should be surgically or conservatively managed. There are over one hundred reported surgical techniques which reconstruct the AC joint, with little indication of which methods achieve the best results. Techniques can generally be considered as: anatomical reduction; CC ligament reconstruction; and anatomical reconstruction. Techniques which implant hardware to reduce the AC joint, such as the hook plate, are commonly implemented, but have been shown to alter the mechanics of the joint significantly, resulting in poor short-term and long-term outcomes. Methods which reconstruct both the acromioclavicular and coracoclavicular ligaments are comparatively new, and early reports suggest that they achieve biomechanical properties similar to the native joint. More focus should be placed on such techniques in the future to determine whether they offer a more suitable approach to improve patient outcomes following AC joint reconstruction.     

锁骨钩钢板在胸锁关节脱位治疗中的应用

目的:探讨应用锁骨钩钢板治疗胸锁关节脱位的方法及疗效。方法:2010年1月至2014年3月,采用锁骨钩钢板固定治疗胸锁关节脱位患者6例,其中男5例,女1例;年龄26～48岁,平均34岁;病程3～20 d.患者均为外伤后患侧胸锁关节肿胀、疼痛,患侧肩关节活动明显受限,经X线片及CT诊断为胸锁关节前脱位,根据Rockwood评分法对术后疗效进行评价。结果:所有患者术后切口愈合良好,外观美观;X线片显示胸锁关节脱位复位良好,钢板位置良好。6例患者均获随访,时间4～18个月,平均12个月。根据Rockwood评分法进行疗效评定:优4 例,良 1 例,可 1 例,未见内固定失效及再脱位,无血管、神经及胸膜等副损伤。结论:锁骨钩钢板能在复位固定胸锁关节的同时保留胸锁关节微动功能,且不损伤胸锁关节软骨面。手术安全性高,固定效果好,患者术后可进行早期康复锻炼。     

Lag Screw Trajectory in Supination-External Rotation Fractures: Does the Direction of the Fibula Lag Screw Have an Effect?

BackgroundThe fracture obliquity of supination-external rotation injury of the fibula is often amenable to lag screw insertion. The purpose of the study was to determine whether biomechanical differences exist between lag screws inserted from an anterior to posterior direction and from a posterior to anterior direction and the thickness of the anterior and posterior fibular cortices were correlated with biomechanical testing.MethodsTen cadaver fibulae were harvested and submitted to material testing following 3.5-mm cortical screw insertion from either an anterior to posterior direction or a posterior to anterior direction. Screw torsional insertion strength and axial pullout strength were measured. Computed tomography images of 40 consecutive patients undergoing preoperative planning for fractures excluding the fibula were examined to define fibular cortical thickness and correlate anatomic findings with the biomechanical testing.ResultsThe axial pullout strength of lag screws inserted from posterior to anterior was significantly greater than that of lag screws inserted from anterior to posterior (p < 0.05). Screw insertion torque measurements demonstrated a similar trend although the data did not reach statistical significance (p = 0.056). The anterior cortex of the distal fibula exhibited a radiographically greater thickness than that of the posterior cortex at the same level (p < 0.001).ConclusionsFor oblique fractures of the distal fibula, posterior to anterior lag screw insertion exhibited improved biomechanical properties when compared with a similar screw inserted from anterior to posterior. These results correlated with the thicker cortical bone present along the anterior fibula.     

Minimalinvasive Akromioklavikulargelenkrekonstruktion (MINAR)

Objective

Reduction and retention of an acromioclavicular (AC) joint dislocation with a button/suture augmentation cerclage (Flip tack, Karl Storz, Tuttlingen, Germany).

Indications

Dislocation of the AC joint (Rockwood III and V). Chronic instabilities in combination with autogenous replacement of the coracoclavicular ligaments. Lateral clavicular fracture with rupture of the coracoclavicular ligaments.

Contraindications

Patients in poor general condition. Local soft-tissue infection. Low-degree dislocation of AC joint (Rockwood I und II). Fracture of the clavicular shaft. Chronic instabilities without ligament replacement.

Surgical Technique

The coracoid process is exposed by a 3 cm long skin incision. A hole is drilled through the coracoid process with the help of a specific aiming device. The suture cerclage is connected to two buttons. One of the buttons is then pushed through the coracoid process. The button is flipped and the suture thereby fixed to the coracoid process. The other anchor is pulled through a hole in the clavicle and the cerclage is secured with a surgical knot after reduction of the AC joint.

Postoperative Management

Application of an abduction splint for 4 weeks (15°).

Results

23 patients with an acute luxation of the AC joint were operated with a minimally invasive coracoclavicular cerclage (five patients with Rockwood type III and 18 patients with Rockwood type V). Mean operative time was 28.6 min. Perior postoperative complications such as nerve and vascular injuries, thoracic injuries, infection, thrombosis, and embolism did not occur. The mean Constant Score was 94.1 points (73–100 points) after a mean of 23.3 months (18–28 months). In two cases, a slight loss of reposition of less than half of the clavicle width in comparison with the contralateral side was observed.     

Arthroskopisch gestützte Techniken zur Versorgung der akuten und chronischen AC-Gelenk-Verletzung

Acute and chronic acromioclavicular (AC) joint dislocation is frequently encountered in the routine clinical practice. This injury can lead to significant impairment of shoulder girdle function. Therapy based on the severity of injury is recommended to re-establish correct shoulder function. The static radiographic Rockwood classification is used to define the degree of dislocation but the clinical aspects and functional x-ray imaging of horizontal AC joint instability should also be considered for selection of the appropriate procedure. Rockwood grades I and II injuries are treated non-operatively with early functional exercise. The approach for Rockwood grade III injuries should be individual and patient-specific, with non-surgical procedures for low functional requirement patients with a high risk for surgical interventions. For patients with high demands on shoulder function surgery is recommended. A detailed diagnostic assessment frequently reveals Rockwood grade III injuries to be type IV injuries. Rockwood types IV and V AC joint dislocations require surgery for sustained stability. Treatment of acute injuries is recommended within 1-3 weeks after trauma but there is no clear evidence of a cut-off for the presence of chronic injuries. Various surgical techniques have been described in the literature. This article presents an arthroscopically assisted technique that addresses both vertical and horizontal instability of the AC joint.     

Lateral fluoroscopic guide to prevent occipitocervical and atlantoaxial joint violation during C1 lateral mass screw placement

Background contextInadvertent perforation of the C0–C1 and C1–C2 joints is one of the potential complications of C1 screw insertion.PurposeTo identify a simple lateral fluoroscopic landmark to help prevent atlantooccipital (C0–C1) and atlantoaxial (C1–C2) joint violations during C1 lateral mass screw insertion.Study designScrew insertion simulation using computed tomography (CT).Patient sampleCervical spine 1.0-mm interval CT scans of 154 patients performed at a single institution between October 2004 and October 2005 were analyzed.Outcome measuresC0–C1 and C1–C2 joint violations during CT-based simulation of C1 lateral mass screw placement.MethodsFine cut CT scans and screw trajectory software was used to simulate insertion of 4.0 mm screws. The entry point was the middle of the junction of the posterior arch and the posterior inferior part of the lateral mass. Zero and fifteen degrees medially angulated trajectories were evaluated. For both, we determined the maximum cranial and caudal angulation that avoided joint violation, and where the screw could safely be directed in the C1 anterior arch on a lateral view using these angulations. We expressed these targeting points as a percentage of the total height of the anterior atlas arch such that 100% represented the cranial border of the arch, 50% the center and 0% the caudal border.ResultsScrew trajectories in 154 patients (308 screws) were evaluated. Using the 15° medial angulation, the C0–C1 joint was safe in all cases when the trajectory was below the 40% point of the anterior arch. The C1–C2 joint was safe when the trajectory was above the 20% point. Using the 0° angulation, safety margin was slightly wider. Because it may be difficult to differentiate between 0° and 15° of medial angulation intraoperatively, we suggest aiming the screw tip between the 20% and 40% points for either trajectory. We call this the “safe zone of C1.”ConclusionsWhen the screw is directed between 0° and 15° medially, it can be inserted without C0–C1 and C1–C2 joint violation if the screw tip trajectory lies between the 20% and 40% points of the anterior atlas arch.     

Eccentric ankle arthritis in the sagittal plane: a novel description of anterior and posterior ankle arthritis

BackgroundTo report radiographic characteristics of anterior and posterior ankle arthritis, which demonstrates the eccentric narrowing of either aspect of the tibiotalar joint in the sagittal plane.MethodsRadiographic analysis of 19 ankles with anterior arthritis and 16 ankles with posterior arthritis was performed, which were defined as having both (1) eccentric narrowing of the anterior or posterior tibiotalar joint space on lateral radiographs and (2) talar tilt angle less than 4 degrees on anteroposterior radiographs. Measured radiographic parameters were: Talar tilt angle, medial distal tibial angle (MDTA), talar center migration (TCM), anterior distal tibial angle (ADTA), tibial axis-to-talus ratio (TT ratio), talo-first metatarsal (Meary) angle, hindfoot alignment angle (HAA), hindfoot moment arm, and mechanical axis deviation (MAD). An Intergroup comparison analysis, including a normal control group, was also performed.ResultsThe TT ratio was significantly different between each group, indicating a distinct talus position in the sagittal plane. The anterior group had a significantly larger TCM than the control group and lower ADTA compared to other groups, indicating medial translation of the talus and anterior opening of the tibial plafond. The posterior group demonstrated a significantly higher Meary angle and lower HAA compared to other groups and lower MDTA compared to the control group, indicating lower medial longitudinal arch, valgus heel alignment, and varus tibial plafond. The MAD was significantly higher in both the anterior and posterior groups than the control group, indicating varus lower limb alignment.ConclusionAnterior ankle arthritis demonstrated anteromedial translation of the talus and anterior opening of the tibial plafond. Posterior ankle arthritis was associated with the lower medial longitudinal arch and hindfoot valgus, indicating an association with flatfoot deformity. Both anterior and posterior ankle arthritis were associated with varus lower limb alignment.     

Anterior dislocation of sternoclavicular joint: A novel surgical technique

IntroductionAnterior sternoclavicular joint dislocation (SCJ) is a relative rare injury, related to high energy trauma. The objective of the present study is to present a novel suture technique for treatment of anterior SCJ traumatic dislocation and to report clinical outcomes from a small case series undergoing this procedure.Patients and MethodsPatients presenting with traumatic anterior SCJ disruption in our institution were eligible to participate. Surgical technique consisted of two bone tunnels drilled in vertical direction from the anterior to the posterior cortex of the manubrium. Analogous to the sternal side of the clavicle, two vertical bone tunnels were drilled from the anterior cortex towards the posterior cortex. A non-absorbable suture was passed though the four holes in a parallel configuration. Then, by pulling the free suture edges the posterior translation of the clavicle was performed. Two additional drill holes, the first in manubrium and the second in clavicle were performed from the anterior cortex to the posterior between the previous bone tunnels. A non-absorbable suture was placed in a simple configuration in order to stabilize the SCJ in the superior–inferior direction. The final follow up was 28.2 months. The mean QuickDASH was used for functional assessment.ResultsSeven patients (6 males and 1 female) with average age of 34,8 years were included in the present study. Two patients suffered from concomitant medial clavicle fracture. At final follow-up (none of the patients had experienced any symptoms of instability of SCJ, no side-to-side difference was observed, while the Mean QuickDASH score was 4.85.ConclusionThe reported technique for SCJ reconstruction in traumatic anterior SCJ dislocations with two sutures has theoretical advantages, since it stabilizes the SCJ in the antero–posterior, as well as the supero- inferior direction. Outcomes from this small case series are favorable. However, more research is desirable to compare different techniques and to conclude to the optimal surgical treatment.