Digital Technology Combined with 3D Printing to Evaluate the Matching Performance of AO Clavicular Hook Plates

BACKGROUND

AO clavicular hook plates have been widely used for treating acromioclavicular (AC) joint dislocation and distal clavicle fractures. Many complications have been reported, and many patients have complained about the discomfort of the plate. However, no study on the impact of clavicular hook plates in AC joint 3D printing models has been reported.

OBJECTIVE

To evaluate the matching performance of hook plates with different hook depths when they were implanted in 3D printing models of normal Chinese AC joints and to propose a further design to achieve a better match.

METHODS

AO clavicular hook plates with two different hook depths of 15 mm and 18 mm were implanted in 3D printing models of forty Chinese normal AC joints. The angle between the distal clavicle and plate (CPA) and the drop between acromion and distal clavicle (ACD) of normal AC joints with and without plates were measured.

RESULTS

Mismatch was found when the hook plates were implanted, with an average CPA of 18.8 ± 5.1° with the 15-mm hook plate and 10.2 ± 4.9° with the 18-mm hook plate. To eliminate the CPA, the ACD decreased by 6.3 ± 1.1 mm with the 15-mm hook plate and 2.9 ± 0.9 mm with the 18-mm hook plate.

CONCLUSIONS

The results revealed that AO clavicular hook plates with different hook depths were very likely to result in over-reduction of the AC joint. It is necessary to bend the hook angle to fit the patient's AC joint to achieve accurate reduction.

Comparison of clavicular hook plate with and without coracoclavicular suture fixation for acute acromioclavicular joint dislocation

Objective

The aim of this study was to compare the clinical and radiographic outcomes of clavicular hook plate fixation with and without coracoclavicular (CC) tape augmentation for the treatment of acute unstable AC dislocation.

Methods

We treated 47 patients (31 men and 16 women; mean age: 47 years (range, 21–81)) with unstable acute AC dislocations (Rockwood III–V) and divided them into two groups according to the treatment modality, with hook plate fixation (hook plate group) or hook plate plus CC tape augmentation (combined group). We assessed radiologic findings, such as subacromial osteolysis and AC osteoarthritis. We also evaluated the clinical outcomes using a visual analogue scale (VAS) for pain, as well as the University of California at Los Angeles (UCLA) Shoulder Rating Scale and the American Shoulder and Elbow Surgeons (ASES) Shoulder Score.

Results

We found that the combined group had less subacromial osteolysis upon radiography, although the CC distance was similar in both groups (119 ± 29.7% of contralateral side CC distance in hook plate group versus 119 ± 34.8% in the combined group, p = 0.77). Compared with the hook plate group, the combined group had a lower VAS score (4.5 ± 2.3 in hook plate group versus 2.3 ± 1.4 in the combined group, p < 0.001), better UCLA scores (19.9 ± 4.9 in hook plate group versus 27.2 ± 4.0 in the combined group, p < 0.001) as well as better ASES scores (51.9 ± 17.8 in hook plate group versus 73.8 ± 13.1 in the combined group, p < 0.001) at 3 and 6 months after surgery.

Conclusion

Hook plate fixation plus CC tape augmentation may prevent subacromial osteolysis and yield better short-term functional outcomes.

Level of Evidence

Level III, Therapeutic Study.

Comparison of Short-Term Clinical Outcomes of Hook Plate and Continuous Loop Double Endobutton Fixations in Acute Acromioclavicular Joint Dislocation

BACKGROUND

This study was conducted to evaluate the clinical outcomes of the acromioclavicular joint (ACJ) fixation with hook plate (HP) and continuous loop double endobutton fixation (CLDE) in the treatment of acute ACJ dislocation.

METHODS

This retrospective study was conducted on eight patients with HP and nine patients with CLDE fixations for acute ACJ dislocations. The subjects were evaluated by various criteria, including disabilities of the Arm, Shoulder, and Hand (DASH), American Shoulder and Elbow Surgeons Standardized Shoulder Assessment (ASES), University of California, Los Angeles (UCLA) shoulder rating scale, Shoulder Constant score, Simple Shoulder Test (SST), and coracoclavicular (CC) distance.

RESULTS

The differences between the mean scores of the visual analog scale for pain, DASH, ASES, UCLA shoulder rating scale, and Shoulder Constant, and SST were statistically significant in favor of the CLDE group. Mean difference of CC distance was 8.6±0.9 mm in the HP group; however, it was 11.6±1.2 mm in the CLDE group. The operation time was shorter in the HP fixation, compared to that in the CLDE fixation (51±13.3 versus 105±9.7 min; P<0.001 and P=0.008). There were six concomitant subacromial erosions and osteoarthritis in the ACJ of the HP group.

CONCLUSION

The CLDE fixation was reported with better clinical outcomes than HP fixation; however, it was a technically demanding procedure. The HP maintained the CC distance better than CLDE with a technically easy application. The HP requires a second surgery for the removal and development of subacromial erosion and osteoarthritis of the ACJ that can be regarded as major concerns.

Complications after surgical treatment of distal clavicle fractures

INTRODUCTION

Distal clavicle fractures have low rates of union when treated with conservative measures. Operative treatment is generally recommended for Neer type II and V. Multiple fixation methods exist with no clear gold standard. The goal of the current study is to assess the outcomes and complications of distal clavicle fractures treated with one of three fixation methods: standard clavicular plate, hook plate or suture fixation about the coracoid.

METHODS

This is a retrospective cohort study of surgically-treated unstable Neer type II and V distal clavicle fractures in adults. These operations were performed by multiple surgeons within a single healthcare system between January 2010 and September 2012. Patients were divided into three cohorts: pre-contoured clavicular locking plates, hook plates, and suture-only fixation methods. Univariate and mulivariate modeling analyses were performed.

RESULTS

A total of 74 distal clavicle fractures comprised the final cohort. Fifty-eight (77%) of these fractures were Neer type II; the remaining 16 (21.6%) were Neer type V. Median follow-up time was 12 months (range 10-28). BMI, smoking status, diabetes, and ASA class were similar among all cohorts. Twenty-one patients were treated with suture fixation alone (28.3%), 37 with a contoured clavicular plate (50%) and 16 with hook plate fixation (21.6%). Twenty-one patients (28.4%) experienced complications, including two hardware failures requiring revision surgery. A total of 10/16 (62.5%) patients with hook plates required hardware removal for irritation, compared to 6/37 (16.2%) with a contoured clavicular plate (OR=8.61, p value=0.001), and none with sutures alone. A total of 3/21 patients (14.2%) treated with suture fixation methods were diagnosed with adhesive capsulitis post-operatively; no patients in the plate fixation groups received this diagnosis. The Neer V group had a higher proportion of any complications (37.5%) compared to Neer II (25.9%), and a higher rate of stiffness (12.5% v. 1.7% in Neer II).

CONCLUSION

This study compared the outcomes of three different fixation methods for unstable distal clavicle fractures. The overall union rate with any method of operative intervention was very high (98.6%), consistent with previous studies. Hook plates had a much higher re-operation rate, mostly owing to a higher incidence of hardware removal, an expected outcome owing to the prominence of these plates in the subacromial space. Contoured clavicular plates were associated with a lower incidence of irritation and hardware removal than hook plates, although one patient in this group experienced loss of fracture fixation and went on to asymptomatic radiographic non-union. Suture-only fixation methods had the lowest rate of re-operation, with only one of 21 procedures resulting in failure and requiring revision. However, there was a significantly higher rate of adhesive capsulitis in the suture fixation cohort, perhaps due to the tethering effect of the clavicle to the coracoid or violation of the rotator interval. While this study supports that most distal clavicle fracture fixation methods can achieve stable union, there is a highly variable complication profile associated with each fixation method. The routine use of hook plate fixation cannot be recommended.

Crossbar Technique for the Failed Clavicular Hook Plate Fixation in an Acute Acromioclavicular Joint Dislocation: Salvage for Acromial Fracture after Clavicular Hook Plate

We experienced acromial erosion and subsequent fracture after the treatment of Rockwood type V acromioclavicular dislocation with hook plate and coracoclavicular ligament augmentation. It was treated by using a surgical technique to address an acromial fracture and subsequent losses of reduction in acromioclavicular joint with two trans-acromial cortical screws (crossbar technique). The reduction state of acromioclavicular joint could be maintained by these two screws. Our crossbar technique could be considered as a good salvage procedure for the reduction loss caused by cutout or significant erosion of acromion after insertion of clavicular hook plate.

Surgical treatment of avulsion fracture around joints of extremities using hook plate fixation

Purpose

This study proposed to access the clinical outcome of avulsion fractures around joints of extremities using the hook plate.

Methods

A total of 60 patients with avulsion fractures of joints admitted in our hospital between January 2011 and June 2016 were performed the surgery of hook plate fixation. Functional recovery was evaluated using the Lysholm knee score, Kaikkonen ankle injury score, Mayo elbow and wrist function score, and Neer shoulder function score.

Results

All the patients were healed within 3 months after surgery with stage I healing incision without vascular or nerve injuries. The average follow-up period was 18.1 months. At the last follow-up, no instability of joints, looseness of internal fixation or traumatic arthritis was observed. Mild joint fibrosis occurred in 5 cases. A total of 57 patients were well recovered with the excellent and good rate of 95%. Three patients with humeral avulsion fracture of the greater tuberosity had shoulder joint adhesion and peri humeral inflammation at the last follow-up due to the poor cooperation for early rehabilitation exercise. In the last follow-ups, the functional score of the affected limb was markedly greater than that in the 3-month follow-ups (p < 0.05).

Conclusion

Hook plate fixation has the therapeutic effect on treating avulsion fractures around joints of extremities with the advantages of reliable fixation, early rehabilitation after operation, high recovery rates of joint function, wide indications, and convenient uses.

Mini hook plate fixation for thumb ulnar collateral ligament avulsion fracture: A technical report

Ulnar collateral ligament (UCL) injuries of the thumb sometimes occur with avulsion fracture. Avulsion fractures generally require open reduction and internal fixation to restore stability of the metacarpophalangeal (MP) joint of the thumb. Although several surgical techniques have been reported, UCL avulsion fractures are still challenging hand injuries to treat and to obtain stable fixation that allows early finger motion because of small size of fragment. This report describes two cases of thumb UCL avulsion fractures that were successfully treated with two-hole mini hook plates by adapting 1.5-mm variable angle locking hand plates. This method allowed for early postoperative rehabilitation and provided stability of the thumb MP joint and satisfactory clinical outcomes. Altogether, hook plate fixation could be an alternative technique for thumb UCL avulsion fracture.

Surgical Outcomes After Fixation of Acromioclavicular Joint Dislocation with Hook Plate and Coracoacromial Ligament Transfer Technique

BACKGROUND:

Treatment of acute and chronic acromioclavicular joint dislocations is still controversial. We aimed evaluation of surgical outcomes after using the combined technique with a hook plate and transposition of the coracoacromial ligament in the treatment of acromioclavicular dislocation.

CASE PRESENTATION:

During two years 4 patients (2 acute and 2 chronic cases) were operated with this technique. Three male and one female with an average 37 (26-43) years old were: three on the right and one of the left side. Rockwood classification was used. The evaluation was done according to Constant score - preoperatively, 3 months after the operation and 3 months after the titanium plate was removed.

CONCLUSION:

Evaluation of the effectiveness using this combined technique show excellent result in all four patients. No surgical site infection and the favourable cosmetic result were present.

Treatment of Anterior Sternoclavicular Joint Dislocation with Acromioclavicular Joint Hook Plate

OBJECTIVE

To evaluate the safety and efficacy of using acromioclavicular joint hook plates for the treatment of anterior sternoclavicular joint dislocation.

METHODS

Ten patients who suffered anterior sternoclavicular joint dislocation were retrospectively analyzed, and underwent acromioclavicular joint hook plate surgeries from January 2015 to May 2017. There were 7 male and 3 female patients, with a mean age of 43.6 years. According to the American Shoulder and Elbow Society (ASES) scoring system, the preoperative physical function had a mean of 83.5.

RESULTS

Reduction and fixation were performed with hook plates in all 10 patients. All patients were followed up, with a mean duration of 16.9 months. There were no complications, no wound infections, and no plate or screw breakages. Movement of the shoulder girdle was improved in all patients. According to the ASES scoring system, the postoperative physical function had a mean of 94.8.

CONCLUSION

The acromioclavicular joint hook plate demonstrates safety and efficacy for the treatment of anterior sternoclavicular joint dislocation. However, there are still some deficiencies that need to be improved.

Treatment of distal clavicle nonunion with and without bone grafting

The management of distal clavicle nonunion represents a challenging task for orthopaedic trauma surgeon. Both the choice of the implant and whether a bone graft is needed are controversial points which must be addressed. Particularly, in the case of a hypertrophic nonunion, grafting may not necessarily be needed, but given a poor underlying biological environment, a bone graft becomes necessary in order to enhance fracture healing. We report the case of a 62-year-old patient who came to us with a hypertrophic nonunion of the left distal clavicle. She was initially treated with a hook plate without bone grafting. After an early peri-implant fracture she was treated again with anatomical S-shaped locking plate associated with autologous cancellous bone graft.

Evaluation of the Acromioclavicular Joint Morphology for Minimizing Subacromial Erosion after Surgical Fixation of the Joint Using a Clavicular Hook Plate

Background

Subacromial erosion remains a major concern after surgical fixation of acromioclavicular (AC) joint using a clavicular hook plate. To minimize postoperative subacromial erosion, we investigated the structural relationship between distal clavicle and acromion around the AC joint by considering the surgical fixation of the joint using the hook plate technique.

Methods

Computed tomography scans of 101 AC joints without any inherent pathology were analyzed. The angle between the distal clavicle and acromion around the AC joint (AC angle), depth of the acromion, differences in height between distal clavicle and acromion (AC height difference), and thickness of distal clavicle and acromion at the AC joint were measured. Descriptive statistics were calculated for each anatomical parameter, and all results were compared between gender groups.

Results

The mean AC angle was 17.1°(range, -8.0° to 39.0°), and the mean AC height difference was 3.5 mm (range, -0.7 to 8.7 mm). Both factors showed very high variability (coefficients of variation=62.6% and 46.6%, respectively). The mean AC angle was significantly higher in the female gender than in the male gender (19.8° vs. 13.8°, p=0.048). The mean acromion thickness and distal clavicular thickness were both significantly thinner in the female group than in the male group (p<0.001).

Conclusions

Taken together, we believe our results might be helpful in minimizing postoperative subacromial erosion when performing surgical fixation of the AC joint using the hook plate, and be valuable in improving future design of the hook plate.

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.

Patient satisfaction after hook plate treatment of bony avulsion fracture of the distal phalanges

BACKGROUND

Bony avulsion fractures of the distal phalanges can result in mallet finger deformity if not treated appropriately. Therefore, only minimally displaced fractures can be treated conservatively with a good outcome, as dislocation occurs very often. Several surgical treatment options have been developed during the past decades. Data concerning the recently developed hook plate are promising. So far, no data concerning the subjective satisfaction with this method have been published. Therefore, we have analyzed the outcome after hook plate implantation using a self-assessment score, which focuses also on subjective parameters and satisfaction.

METHODS

Standardized questionnaires (self-assessment scores and SF-36 questionnaire) were sent to each patient treated with a hook plate due to fracture of the distal phalanx, type Doyle IVb and IVc. Clinical data were evaluated according to the medical record. Scores given per question range from 0 to 10, 10 is the worst and 0 the best outcome.

RESULTS

From 69 patients treated, 38 (58%) were enrolled. The whole collective (n = 38) reached a score of 39.7 ± 28.7 points, while men had slightly better results. Men (n = 24) achieved 37.3 ± 27.9 points, women (n = 14) 43.9 ± 30.7 points. Women had significantly better results when analyzed later than 12 months after surgery (52.1 ± 27.9 vs. 29.1 ± 32.8), whereas no changes could be detected in the male group (37.1 ± 29.9 vs. 37.4 ± 27.6). Overall, men were slightly more satisfied than women. Most satisfaction was found regarding pain and fine motor skills (0-0.46 points). Esthetic aspect and nail deformities (3.65 points average) led to the highest dissatisfaction. No differences in the SF 36 score could be detected.

CONCLUSIONS

The hook plate is not only a convenient method but it also results in high patient satisfaction. Nail deformities are challenging; however, with increasing experience of the surgeon they decrease. SF 36 score is not an appropriate testing tool for this problem.

Treatment of AC dislocation by reconstructing CC and AC ligaments with allogenic tendons compared with hook plates

BACKGROUND

The purpose of this study was to compare outcomes between allograft reconstruction and hook plate fixation for acute dislocation of the acromioclavicular joint with a minimum 2-year follow-up.

METHODS

A retrospective comparative study of patients treated for acute acromioclavicular joint dislocation from February 2010 to December 2014 in our hospital, consisting of 16 patients who were followed-up, was performed. Eight patients were treated for acute AC dislocation and underwent surgical reconstruction as follows: the coracoclavicular and acromioclavicular ligaments were reconstructed with the allogenic tendon. The other eight patients were treated with hook plates to maintain the AC joint reset. At the latest follow-up, radiographic analysis and the Constant and University of California-Los Angeles (UCLA) scores were used to evaluate shoulder function. The satisfaction of the patients in terms of the efficacy and visual analog scale (VAS) data were also recorded.

RESULTS

After an average follow-up of 30.3 months (range 24-46 months), no patient had dislocated their joint again at the final follow-up based on X-ray examination. The Constant score was 94.4 for the allogenic tendon group and 93.8 for the hook plate group (P = 0.57). According to the UCLA scale (P = 0.23) or VAS (P = 0.16), we found no significant difference between the two groups. All patients reported that they were very satisfied or satisfied with the outcome of surgery, and no significant difference (P = 0.08) was found between the two groups.

CONCLUSIONS

The use of allogenic tendon for reconstruction of the coracoclavicular and acromioclavicular ligaments shows excellent outcomes in terms of the recovery of clinical function or radiographic outcomes for acute AC dislocation. Compared with the hook plate, the hardware did not need to be removed.

Single coracoclavicular suture fixation with Mersilene tape versus hook plate in the treatment of acute type V acromioclavicular dislocation: a retrospective analysis

BACKGROUND

Here, we compared the clinical and radiographic outcomes between coracoclavicular (CC) fixation with Mersilene tape and hook plate for acute unstable acromioclavicular (AC) joint dislocation treatment.

METHODS

We enrolled 49 patients with unstable acute AC dislocation who, between January 2010 and January 2014, underwent surgery with single CC suture fixation with Mersilene tape (M group, 25 cases) or clavicle hook plate (H group, 24 cases). In M and H groups, the average age was 43.7 (range 18-72) and 42.0 (range 17-84) years, the male to female ratio of each group was 15:20 and 19:5, and the injured side left to right ratio was 12:13 and 11:13, respectively. All patients were right-handed. We retrospectively compared the operation time, complication rate, visual analog scale (VAS), University of California at Los Angeles (UCLA) shoulder rating scale, Oxford shoulder scores, and the radiographic outcomes based on reduction loss of CC distance on postoperative follow-up.

RESULTS

No significant difference in patient demographics between the two groups in age (p = 0.709), gender (p = 0.217), time from injury to surgery (p = 0.863), and injured side (p = 1.000). The mean follow-up was 26.2 months (range 24-35 months). Nine cases of reduction loss (36%) and one of distal clavicle osteolysis (4%) were noted in the M group. CC distance improvement in the H group was significantly superior to that in the M group at 3 months (before hook plate removal, p < 0.001) and 12 months postoperatively (after hook plate removal, p = 0.004), while subacromial erosions were revealed in nine cases (37.5%) in the H group. No significant difference in operative time (p = 0.846), complication rate (p = 1.000), VAS (p = 0.199), mean UCLA shoulder rating scale (p = 0.353), and Oxford shoulder (p = 0.224) scores between the two groups.

CONCLUSIONS

Both hook plate and Mersilene tape fixations provided temporary stabilization of acute type V AC dislocation and yielded comparable clinical outcomes. The hook plate provided better maintenance of reduction of radiographic outcomes. CC suture fixation with Mersilene tape may serve as an alternative method of stabilization which provides acceptable outcome without the need of implant removal.

Comparison of hook plate with versus without double-tunnel coracoclavicular ligament reconstruction for repair of acute acromioclavicular joint dislocations: A prospective randomized controlled clinical trial

PURPOSE

This study was designed to compare the surgical outcomes of a hook plate with double-tunnel coracoclavicular (CC) ligament reconstruction by conjoined tendon transfer versus single hook plate surgery for the repair of acute type of Rockwood type III and V acromioclavicular (AC) joint dislocations.

METHODS

The study cohort included 62 patients with acute (within 6 weeks after trauma) Rockwood type III and V AC joint dislocations who underwent surgery from February 2012 to September 2015. The patients were randomly allocated to the ligament reconstruction group (LR group, n = 31) or the single hook plate group (HP group, n = 31). In both groups, reduction of the AC joint by hook plate and repair of the ruptured AC ligament with absorbable Vicryl sutures were performed homoplastically. The lateral half of the short tendon of the biceps brachii muscle and the lateral half of the flexor tendon were used to reconstruct the trapezoid and conoid ligaments, respectively. Differences in surgical duration, intraoperative blood loss, incision length, and total cost were compared between the two groups. Furthermore, the preoperative and postoperative visual analogue score (VAS), postoperative American Shoulder and Elbow Surgeons (ASES) score, Constant-Murley score (CMS), Karlsson score, complication rates, and patient satisfaction at the last follow-up were compared to evaluate the curative effects of the surgical treatments. Magnetic resonance imaging (MRI) after hook plate removal was used to evaluate the reconstructed ligaments and tendon-bone interface.

RESULTS

In total, 25 patients in the LR group and 26 in the HP group completed the follow-up. There were no statistically significant differences in age, sex, Rockwood type, placing time, total cost, and follow-up duration between the LR and HP groups (p > 0.05). However, as compared with the HP group, the surgical duration and incision length were longer in the LR group (92.08 ± 19.25 vs. 56.54 ± 21.29 min and 13.64 ± 0.90 vs. 6.65 ± 1.01 cm, respectively, p < 0.05). In addition, there was no significant difference in preoperative VAS scores, but the postoperative VAS score was lower in LR group than in the HP group (2.52 ± 1.19 vs. 4.12 ± 1.45, respectively, p < 0.05). Moreover, patients in LR group had a remarkable higher CMS and ASES score (89.56 ± 2.80 vs. 79.31 ± 4.97 and 92.60 ± 2.79 vs. 82.35 ± 3.44, respectively, p < 0.05). The overall excellent or good result rate, as evaluated by the Karlsson score, was 92.00% (23/25) and 50.00% (13/26), respectively (p < 0.05). MRI findings revealed good condition of the reconstructed ligaments and tendon-bone interface. The incidence of complications was lower and the satisfaction rate was higher in the LR group than in the HP group (1/25 vs. 16/26 and 23/25 vs. 14/26, respectively, p < 0.05).

CONCLUSIONS

The overall surgical effect of the use of a hook plate combined with double-tunnel CC ligament reconstruction is superior to single hook plate surgery for the repair of acute Rockwood type III and V AC joint dislocations.

Peroneus brevis tendon in proximal 5th metatarsal fractures: Anatomical considerations for safe hook plate placement

INTRODUCTION

The peroneus brevis tendon (PBT) inserts into the proximal aspect of the 5th metatarsal. Metatarsal bone fractures are encountered to be the most common fractures in the foot with predominantly fractures at the base of the fifth metatarsal bone. Mechanism of injury and treatment of the proximal 5th metatarsal fractures vary due to the complex anatomy and diverse biomechanical properties. The purpose of this study was to analyze the footprint of the PBT with regards to the proximal 5th metatarsal fractures and to define a "safe zone" for hook plate placement.

MATERIALS AND METHODS

Forty-one (41) fixed human lower leg specimens were dissected to expose the PBT insertion. The following footprint characteristics were evaluated: area of insertion (AOI) (mm²), length (mm), width (mm), shape and insertional variations. The position of the main PBT footprint was localized according to the Lawrence and Botte classification for the proximal 5th metatarsal fractures (Zone I-III). A "safe zone" was defined for the fracture-specific hook plate placement.

RESULTS

In 25 (61%) feet the PBT footprint was situated in Zone I and in 16 feet (39%) in Zone I&II. The mean AOI, length and width measured 54.5 mm² (SD 16.5), 16.0 mm (SD 5.1) and 4.7 mm (SD 1.4), respectively. Analysis of the footprint shapes revealed four different shape types: kidney (29.3%), diamond (22.0%), crescent (31.7%) and oval (17.0%). A "safe zone" for hook plate placement without or minimal interference of the PBT at its insertion could be defined at the lateral aspect of the 5th metatarsal.

CONCLUSION

The majority of the PBT footprints were found in Zone I. Hook plate placement demonstrated to be safe when placed strictly laterally at the proximal aspect of the 5th metatarsal. Precise knowledge of the peroneus brevis anatomy may help to better understand the biomechanical aspects of the proximal 5th metatarsal fractures.

[Current aspects and new techniques in dislocation of the shoulder joint]

With 12% of all injuries concerning the shoulder, acromioclavicular (AC) joint dislocations are a common injury especially in young and active patients. The Rockwood classification is widely accepted, which differentiates between six types depending on the degree of injury and the vertical dislocation. Because the classification does not adequately address the horizontal instability, its benefits are questionable and there is currently no consensus. For this reason, the classification and the therapy of these injuries are increasingly becoming the subject of scientific investigations. Whereas conservative treatment for type I and II injuries and operative treatment for type IV-VI injuries are widely accepted, there is still no agreement in treating type III lesions. The goal of this review article is to present the current evidence for the diagnostics, different classifications and therapeutic possibilities.

Short-term outcomes of arthroscopic TightRope® fixation are better than hook plate fixation in acute unstable acromioclavicular joint dislocations

AIM

The aim of this study was to compare the short-term outcomes of arthroscopic TightRope^® fixation with that of hook plate fixation in patients with acute unstable acromioclavicular joint dislocations.

PATIENTS AND METHODS

We conducted a prospective case-control study of twenty-six patients with an acute ACJ dislocation who underwent surgical repair with either an arthroscopic TightRope^® fixation or a hook plate from 2013 to 2016. Clinical and radiological data were collected prospectively. Clinical outcomes were evaluated using the Constant Score, the University of California at Los Angeles (UCLA) Shoulder Score, Oxford Shoulder Score as well as the visual analogue scale. Radiological outcomes were assessed with the coracoclavicular distance (CCD).

RESULTS

Sixteen patients underwent arthroscopic TightRope^® fixation, while 10 patients underwent hook plate fixation. There were no significant differences in the preoperative variables except for the mean UCLA 4b infraspinatus score (TightRope^® 2.8 vs. hook plate 3.8; p = 0.030). Duration of surgery was significantly longer in the TightRope^® group. At 1 year post-operatively, the TightRope^® group had a significantly better Constant Score and CCD with no complications. All patients with hook plate fixation had to undergo a second procedure for removal of implant, and 3 patients had complications.

CONCLUSIONS

Arthroscopic TightRope^® fixation is a good option for the treatment of acute unstable ACJ dislocations. It has better short-term clinical and radiological outcomes as well as lesser complications when compared to hook plate fixation.

LEVEL OF EVIDENCE

Therapeutic, Level III.

Morphological analysis of acromion and hook plate for the fixation of acromioclavicular joint dislocation

PURPOSE

Acromioclavicular (AC) joint dislocation is a common sports injury. Hook plate fixation is currently widely used to treat this injury, as it can promote the natural healing of the ligament with good clinical outcomes. However, subacromial erosion and impingement are frequently observed post-operatively. It was hypothesized that the morphology and the contact characteristics between the hook portion and the acromion are the main causes of complications after hook plate fixation with the currently available commercial designs.

METHODS

Three-dimensional reconstructed models of the AC joint obtained from the computed tomographic scans of 23 male and 23 female patients (mean age, 61.1 ± 6.3 years) were evaluated, and multiple anatomical parameters were measured. For the subacromial positioning of the hook plate, an actual hook plate (Synthes Inc., West Chester, PA, USA) was scanned, and the contact between the hook plate and the acromion was estimated.

RESULTS

The thicknesses of the acromion and distal clavicle were 9.7 ± 1.5 mm (10.7 mm in men; 8.6 mm in women) and 11.3 ± 1.6 mm (11.6 mm in men; 10.0 mm in women), respectively. The width of the acromion was 28.5 ± 3.6 mm. The mean inclination angle between the hook plate and the acromion was 29.3° ± 9.7° (27.9° in men; 30.6° in women). The hook plate made a point contact with the acromion at 9.2 ± 3.3 mm (31.5 %) from the lateral end of the acromion.

CONCLUSIONS

The results revealed that the hook made a pinpoint contact with the undersurface of the acromion, and this might explain why complications commonly occur after hook plate fixation. The force concentration phenomenon associated with the hook plate of existing designs results from cases of morphological mismatch, such as excessive inclination and improper occupation of the subacromial space.

Post-operative outcomes and complications of suspensory loop fixation device versus hook plate in acute unstable acromioclavicular joint dislocation: a systematic review and meta-analysis

BACKGROUND

Treatment of acute (≤3 weeks) acromioclavicular joint dislocation type III-VI is still controversial. Currently, the two modern techniques that are widely used are hook plate (HP) fixation and coracoclavicular ligament fixation using a suspensory loop device that consists of either a tightrope (single or double), endo-button (single or double), or synthetic ligament and absorbable polydioxansulfate sling.

MATERIALS AND METHODS

This systematic review was conducted according to the PRISMA guidelines. Relevant studies that reported Constant-Murley score (CMS), Pain Visual Analog score (VAS) and postoperative complications of either technique were identified from Medline and Scopus from inception to 5 October 2015.

RESULTS

Sixteen studies were included for the analysis of HP fixation, and 25 studies were included for analysis of loop suspensory fixation (LSF). Pooling of mean CMS and VAS scores gave 90.35 (95% CI 87.16, 93.54), 1.51 (95% CI 0.73, 2) in the HP group, and 92.48 (95% CI 90.91, 94.05), 0.32 (95% CI 0, 0.64) in the suspensory loop devices group, respectively. The pooled unstandardized mean differences (UMD) scores of CMS and VAS in LSF were 2.13 (95% CI -1.43, 5.69) and -1.19 (95% CI -2.03, -0.35) when compared to hook plating. The pooled prevalence of LSF and hook plating were 0.08 (95% CI 0.06, 0.10) and 0.05 (95% CI 0.02, 0.08) scores. The chance of having complications in the LSF group was 1.69 (95% CI 1.07, 2.60), which was statistically significantly higher than in the HP group.

CONCLUSION

LSF have higher shoulder function scores (CMS) and lower postoperative pain when compared to HP fixation; however, there are higher complication rates with LSF when compared to hook plating.

LEVEL OF EVIDENCE

IV.

Plate fixation in periprosthetic femur fractures Vancouver type B1-Trochanteric hook plate or subtrochanterical bicortical locking?

INTRODUCTION

Proximal plate fixation in periprosthetic femur fractures can be improved by plate anchorage in the greater trochanter (lateral tension band principle) or bicortical locking screw placement beside the prosthesis stem in an embracement configuration. Both concepts were compared in a biomechanical test using a femoral hook plate (hook) or a locking attachment plate (LAP).

METHODS

After bone mineral density (BMD) measurement in the greater trochanter, six pairs of fresh frozen human femora were assigned to two groups and instrumented with cemented hip endoprostheses. A transverse osteotomy was set distal to the tip of the prosthesis, simulating a Vancouver B1 fracture. Each pair was instrumented using a plate tensioner with either hook or LAP construct. Cyclic testing (2Hz) with physiologic profile and monotonically increasing load was performed until catastrophic failure. Plate stiffness was compared in a four-point-bending-test. Paired student's-t-test was used for statistical evaluation (p<0.05).

RESULTS

Mean BMD was 250mgHA/ccm±47. The hook construct exhibited a significantly (p=0.015) lower number of cycles and load to failure (26'177cycles±2777; 3'118N±778) correlating significantly with BMD (R²=0.83; p=0.04) compared to the LAP construct (37'423cycles±5'299; 4'242N±1'030) (R²=0.71;p=0.11). BMD was a significant covariate (p=0.01). Plate stiffness was in a comparable range (hook Plate 468N/mm±7; LCP 445N/mm±6).

CONCLUSION

Subtrochanterically placed LAP provides an increased fixation strength under repetitive loading compared to hook plate fixation in the greater trochanter. Trochanteric fixation is highly BMD dependent and may be restricted to major greater trochanteric involvement requiring stabilization.

Acute high-grade acromioclavicular joint injuries: quality of life comparison between patients managed operatively with a hook plate versus patients managed non-operatively

INTRODUCTION

Surgical indication for acromioclavicular joint (ACJ) injuries still represents a reason for shoulder and trauma debate. In high-grade injuries, surgery is advocated because some of the non-operatively managed patients may have persistent shoulder pain that could make them unable to return to their previous activity. It has been shown that many of the patients with high-grade ACJ injuries that are managed non-operatively involve the development of scapular dyskinesis, situation that may result in loss of strength and weakness. On the other side, it has been widely reported that the period while the hook plate is present involves functional limitations and pain. The purpose of this study was to compare the quality of life (QoL) of patients with acute high-grade ACJ injuries (Rockwood grade III-V), managed operatively with a hook plate versus the QoL of patients managed non-operatively, 24 months or more after shoulder injury.

PATIENTS AND METHODS

Patients with acute high-grade ACJ injuries managed operatively (hook plate) or non-operatively, between 2008 and 2012 were included. The QoL was evaluated by means of the Health Survey questionnaire (SF36), the Visual Analogue Scale (VAS) for pain, the Disabilities of the Arm, Shoulder and Hand (DASH) questionnaire, the Constant score and the Global Satisfaction (scale from 0 to 10) assessed at the last follow-up visit. The presence of scapular dyskinesis was assessed. Comparison between groups was made.

RESULTS

Thirty-two patients were included: 11 hook plate-group (PLATE group) (5 Rockwood III and 6 V) and 21 conservative-group (CONS group) (4 Rockwood III and 17 V). The mean age was 41 [19-55] years old for the PLATE group and 38 [19-55] for the CONS group (p = 0.513). The mean follow-up was 32.50 ± 11.64 months for the PLATE group and 34.77 ± 21.98 months for the CONS group (p = 0.762). The mean results of the questionnaires assessed at the last follow-up visit were: (1) physical SF36 score (PLATE group 53.70 ± 4.33 and CONS group 52.10 ± 6.11, p = 0.449); (2) mental SF36 score (PLATE group 53.06 ± 6.10 and CONS group 56.99 ± 6.47, p = 0.110); (3) VAS for pain (PLATE group 1.45 ± 1.51 and CONS group 1.50 ± 1.79, p = 0.943); (4) DASH score (PLATE group 4.79 ± 5.60 and CONS group 5.83 ± 6.76, p = 0.668); (5) Constant score (PLATE group 91.36 ± 6.84 and CONS group 91.05 ± 7.35, p = 0.908); (6) Global Satisfaction (PLATE group 8.00 ± 1.18 and CONS group 8.45 ± 1.73, p = 0.449). There was evidence of scapular dyskinesis in 18 % (2/11) of the patients of the PLATE group and in 52.4 % (11/21) of the patients of the CONS group (p = 0.127).

CONCLUSIONS

Patients with acute high-grade ACJ injuries managed operatively with a hook plate may have the same QoL and self-reported questionnaires than patients with high-grade ACJ injuries managed non-operatively, 24 months or more after shoulder injury. If surgery is advocated for this type of injury, the orthopedic population must be aware that the hook-plate system might not represent the most suitable option.

LEVEL OF EVIDENCE

Level IV therapeutic; retrospective comparative study.

Clinical and radiological results on the fixation of Neer type 2 distal clavicle fractures with a hook plate

Objective

The aim of this study was to analyze the clinical and functional results of hook plate fixation in Neer type 2 distal clavicle fractures.

Methods

We retrospectively analyzed 16 patients (11 males, 5 females) who were diagnosed with Neer type 2 distal clavicle fractures and treated with hook plate fixation between 2013 and 2014. Mean age was 38 (range: 27–61), and mean follow-up time was 14.3 (range: 12–18) months. Complications seen on radiographs were implant failure and subacromial osteolysis. The clinical results were evaluated with modified UCLA (University of California Los Angeles) scoring system.

Results

Bone union was achieved in all patients at the end of the first 4 months. Mean modified UCLA score was 32.75 (range 31–35). In 12 patients (68%), the implants had to be removed due to complications. After removal, the complaints regressed and shoulders' range of motion increased.

Conclusion

Clinical and radiological results on the fixation of Neer type 2 distal clavicle fractures with a hook plate are good in terms of fracture union and function. The major disadvantage of the method was the requirement of early implant removal due to the hardware related complications and good results can be achieved only after plate removal. Optimizing the length of hook plate may lower the rate of complications.

Level of evidence

Level IV, Therapeutic study.

Comparison of surgical outcomes between fixation with hook plate and loop suspensory fixation for acute unstable acromioclavicular joint dislocation: a systematic review and meta-analysis

Treatment of acute (≤4 weeks) high-grade acromioclavicular (AC) joint separation (types III-VI) is still controversial. Currently, the two modern techniques that are widely used include hook plate fixation and coracoclavicular (CC) ligament fixation using a suspensory loop device (tightrope, synthetic ligament or absorbable polydioxansulfate sling). These techniques are both reported to have superior clinical outcomes. This systematic review and meta-analysis aimed to assess and compare clinical outcomes of hook plate fixation versus fixation of the CC ligament using a loop suspensory fixation (LSF) device for the treatment of AC joint injury. These clinical outcomes consist of the Constant-Murley score (CMS), pain visual analog score (VAS) and postoperative complications. Relevant comparative studies were identified from MEDLINE and Scopus from inception to October 5, 2015. Five of 571 studies were eligible; 5, 3, 3, and 5 studies were included in the pooling of CMS, pain VAS, surgical time and postoperative complications, respectively. The unstandardized mean difference (UMD) of the CMS for LSF was 4.43 [95 % confidence interval (CI) 0.73, 8.14], which was statistically significantly higher than the CMS in hook plate fixation. For VAS, the UMD was 0.02 points (95 % CI -3.54, 3.73) higher than LSF but without statistical significance. The surgical time of LSF was 16.21 min (95 % CI 6.27, 26.15) statistically significantly higher than hook plate fixation. LSF had a lower chance of postoperative complications by 0.62 units (95 % CI 0.30, 1.32) when compared to hook plate fixation, but this also was not statistically significant. In acute high-grade AC joint injuries, loop suspensory fixation had higher postoperative functional CMS and mean surgical time when compared to hook plate fixation. However, for postoperative VAS and complication rates, there were no statistically significant differences between groups.