PEEK biomaterials in trauma, orthopedic, and spinal implants

Since the 1980s, polyaryletherketones (PAEKs) have been increasingly employed as biomaterials for trauma, orthopedic, and spinal implants. We have synthesized the extensive polymer science literature as it relates to structure, mechanical properties, and chemical resistance of PAEK biomaterials. With this foundation, one can more readily appreciate why this family of polymers will be inherently strong, inert, and biocompatible. Due to its relative inertness, PEEK biomaterials are an attractive platform upon which to develop novel bioactive materials, and some steps have already been taken in that direction, with the blending of HA and TCP into sintered PEEK. However, to date, blended HA-PEEK composites have involved a trade-off in mechanical properties in exchange for their increased bioactivity. PEEK has had the greatest clinical impact in the field of spine implant design, and PEEK is now broadly accepted as a radiolucent alternative to metallic biomaterials in the spine community. For mature fields, such as total joint replacements and fracture fixation implants, radiolucency is an attractive but not necessarily critical material feature.

A Concert between Biology and Biomechanics: The Influence of the Mechanical Environment on Bone Healing

In order to achieve consistent and predictable fracture healing, a broad spectrum of growth factors are required to interact with one another in a highly organized response. Critically important, the mechanical environment around the fracture site will significantly influence the way bone heals, or if it heals at all. The role of the various biological factors, the timing, and spatial relationship of their introduction, and how the mechanical environment orchestrates this activity, are all crucial aspects to consider. This review will synthesize decades of work and the acquired knowledge that has been used to develop new treatments and technologies for the regeneration and healing of bone. Moreover, it will discuss the current state of the art in experimental and clinical studies concerning the application of these mechano-biological principles to enhance bone healing, by controlling the mechanical environment under which bone regeneration takes place. This includes everything from the basic principles of fracture healing, to the influence of mechanical forces on bone regeneration, and how this knowledge has influenced current clinical practice. Finally, it will examine the efforts now being made for the integration of this research together with the findings of complementary studies in biology, tissue engineering, and regenerative medicine. By bringing together these diverse disciplines in a cohesive manner, the potential exists to enhance fracture healing and ultimately improve clinical outcomes.

Calcaneal Fractures - Should We or Should We not Operate?

The best treatment for displaced, intraarticular fractures of the calcaneum remains controversial. Surgical treatment of these injuries is challenging and have a considerable learning curve. Studies comparing operative with nonoperative treatment including randomized trials and meta-analyses are fraught with a considerable number of confounders including highly variable fracture patterns, soft-tissue conditions, patient characteristics, surgeon experience, limited sensitivity of outcome measures, and rehabilitation protocols. It has become apparent that there is no single treatment that is suitable for all calcaneal fractures. Treatment should be tailored to the individual fracture pathoanatomy, accompanying soft-tissue damage, associated injuries, functional demand, and comorbidities of the patient. If operative treatment is chosen, reconstruction of the overall shape of the calcaneum and joint surfaces are of utmost importance to obtain a good functional result. Despite meticulous reconstruction, primary cartilage damage due to the impact at the time of injury may lead to posttraumatic subtalar arthritis. Even if subtalar fusion becomes necessary, patients benefit from primary anatomical reconstruction of the hindfoot geometry because in situ fusion is easier to perform and associated with better results than corrective fusion for hindfoot deformities in malunited calcaneal fractures. To minimize wound healing problems and stiffness due to scar formation after open reduction and internal fixation (ORIF) through extensile approaches several percutaneous and less invasive procedures through a direct approach over the sinus tarsi have successfully lowered the rates of infections and wound complications while ensuring exact anatomic reduction. There is evidence from multiple studies that malunited displaced calcaneal fractures result in painful arthritis and disabling, three-dimensional foot deformities for the affected patients. The poorest treatment results are reported after open surgical treatment that failed to achieve anatomic reconstruction of the calcaneum and its joints, thus combining the disadvantages of operative and nonoperative treatment. The crucial question, therefore, is not only whether to operate or not but also when and how to operate on calcaneal fractures if surgery is decided.

Posterior fixation of subaxial cervical spine fractures in patients with ankylosing spondylitis

Cervical spine fractures in patients with ankylosing spondylitis are serious and potentially lethal injuries with high complication rates. Treatment obstacles include long lever arms that generate large forces on any fixation device, osteoporosis, and, usually, kyphotic deformity. The Olerud Cervical Fixation System (OC), with cervical pedicle screws and rods, offers an opportunity to create a biomechanically stable posterior fixation in these complicated cases. The present study is a retrospective chart review and a radiological follow-up of patients with this diagnosis, treated at our department between 1995 and 2000. Nineteen patients (two women) with a mean age of 60 years (32-78 years) were included. The fracture levels were predominantly C5-C6 (five patients) and C6-C7 (five patients). All patients were treated with a long posterior fixation with the OC, and in four patients this was combined with an anterior plate fixation. One patient with severe lordosis also received a short posterior plate fixation. The patients' notes and plain radiographs have been reviewed. Five patients died during the post-operative follow-up period; the others had a mean follow-up time of 24 months (10-55 months). Eleven patients had no neurological deficits preoperatively. One of them developed moderate weakness in his right arm, postoperatively, due to a misplaced pedicle screw in the right pedicle of C5. However, after extraction of the screw he almost totally recovered in 6 months. Eight patients had neurological deficits. Two were paraplegic; two had motor weakness combined with sensory deficiency, and four had a sensory deficiency. Two of the patients with neurological deficits improved postoperatively, but the others were unchanged. Peroperative problems were recorded in five patients; one C6 pedicle was perforated, and two patients had pedicles on one or more levels that the surgeon was not able to probe. In one of the latter patients, transfacet screws were chosen, instead, for one of the levels. Extensive peroperative bleeding was encountered in two patients. One deep-wound infection was noted, postoperatively, and required surgical drainage, but no patients have been re-operated due to loosening of the instrument or to healing problems. In conclusion, the results of the present study indicate that the OC--and possibly other similar long-fixation systems that allow using both pedicle screws and lateral mass screws rigidly connected to a rod--is suited for treating subaxial cervical spine fractures in patients with ankylosing spondylitis, allowing high healing rates.

Shoulder function after surgical treatment of displaced fractures of the humeral shaft: a randomized trial comparing antegrade intramedullary nailing with minimally invasive plate osteosynthesis

BACKGROUND

Minimally invasive plate osteosynthesis for humeral shaft fractures has been described recently, but there are no randomized studies comparing the clinical results for shoulder function between this technique and locking intramedullary nailing.

METHODS

A prospective randomized study was performed. Forty-one humeral shaft fractures (40 patients) were randomized to be treated with a minimally invasive plate (n = 21) or a locking intramedullary nail (n = 19). Clinical and radiographic outcome assessments were conducted at 1 year postoperatively. Shoulder function was the primary outcome, as measured by the University of California, Los Angeles Shoulder Scale. Elbow function was measured by the Broberg-Morrey score, and fracture consolidation and complications were the main secondary outcomes.

RESULTS

At 1 year postoperatively, no significant difference was found with regard to shoulder function according to the University of California, Los Angeles scale between the minimally invasive plate and locking intramedullary nail (31.4 points vs 31.2 points, P = .98). There was also no difference in elbow function (94.8 points vs 94.1 points, P = .96). Complications were similar between the groups, without significant differences regarding infection (P > .99), symptomatic shoulder stiffness (P = .488), and neurapraxia of the lateral cutaneous nerve of the forearm (P = .475). Fracture union was achieved in all but 1 patient (2.4%) in the intramedullary nail group within 1 year after the surgical procedure.

CONCLUSION

There is no significant difference in shoulder function between antegrade intramedullary nailing and minimally invasive plate osteosynthesis for the treatment of displaced humeral shaft fractures, despite the limited power of our study.

A systematic review of the use of titanium versus stainless steel implants for fracture fixation

Background:

Controversy exists regarding the use of titanium and stainless steel implants in fracture surgery. To our knowledge, no recent, comprehensive review on this topic has been reported.

Purpose:

To perform a systematic review of the evidence in the current literature comparing differences between titanium and stainless steel implants for fracture fixation.

Methods:

A systematic review of original research articles was performed through the PubMed database using PRISMA guidelines. Inclusion criteria were English-language studies comparing titanium and stainless steel implants in orthopaedic surgery, and outcome data were extracted.

Results:

The search returned 938 studies, with 37 studies meeting our criteria. There were 12 clinical research articles performed using human subjects, 11 animal studies, and 14 biomechanical studies. Clinical studies of the distal femur showed the stainless steel cohorts had significantly decreased callus formation and an increased odds radio (OR 6.3, 2.7-15.1; P < .001) of nonunion when compared with the titanium plate cohorts. In the distal radius, 3 clinical trials showed no implant failures in either group, and no difference in incidence of plate removal, or functional outcome. Three clinical studies showed a slightly increased odds ratio of locking screw breakage with stainless steel intramedullary nails compared with titanium intramedullary nails (OR 1.52, CI 1.1-2.13).

Conclusion:

Stainless steel implants have equal or superior biomechanical properties when compared with titanium implants. However, there is clinical evidence that titanium plates have a lower rate of failure and fewer complications than similar stainless steel implants in some situations. Although our review supports the use of titanium implants in these clinical scenarios, we emphasize that further prospective, comparative clinical studies are required before the conclusions can be made.

Plate versus titanium elastic nail in treatment of displaced midshaft clavicle fractures: A comparative study

BACKGROUND

With changing trends in treatment of displaced midshaft clavicle fractures (DMCF), plating remains the standard procedure for fixation. An attracting alternative method of fixation is the titanium elastic nailing (TEN). However, prospective randomized studies comparing the two methods of fixation are lacking. We assessed the effectiveness of minimally invasive antegrade TEN and plating technique for the treatment of DMCF.

MATERIALS AND METHODS

80 unilateral displaced midclavicular fractures operated between October 2010 and May 2013 were included in study. This prospective comparative study was approved by the local ethical committee. Followups were at 2(nd) and 6(th) weeks and subsequently at 3, 6, 12, 18 and 24 months postoperatively. Primary outcome was measured by the Constant score, union rate and difference in clavicular length after fracture union. Secondary outcome was measured by operative time, intraoperative blood loss, wound size, cosmetic results and complications.

RESULTS

During analysis, we had 37 patients in the plate group and 34 patients in the TEN group. There was no significant difference in Constant scores between the two groups. However, faster fracture union, lesser operative time, lesser blood loss, easier implant removal and fewer complications were noted in the TEN group.

CONCLUSION

The use of minimally invasive antegrade TEN for fixation of displaced midshaft clavicle fractures is recommended in view of faster fracture union, lesser morbidity, better cosmetic results, easier implant removal and fewer complications; although for comminuted fractures plating remains the procedure of choice.

Robot-assisted percutaneous screw placement combined with pelvic internal fixator for minimally invasive treatment of unstable pelvic ring fractures

Purpose

The purpose of this study was to investigate the safety and efficacy of the combination of robot‐assisted percutaneous screw placement and pelvic internal fixator (INFIX) for minimally invasive treatment of unstable anterior and posterior pelvic ring injuries.

Methods

From September 2016 to June 2017, twenty‐four patients with unstable anterior and posterior pelvic ring injuries were treated with TiRobot‐assisted percutaneous sacroiliac cannulated screw fixation on the posterior pelvic ring combined with robot‐assisted pedicle screw placement in the anterior inferior iliac spine along with INFIX on the anterior pelvic ring. The results of the treatment, including surgery duration, fluoroscopy frequency, total drilling, amount of blood loss, fracture healing time, and postoperative functional outcomes were recorded and compared with another 21 similar patients who underwent conventional manual positioning surgery.

Results

The TiRobot group incurred significantly shorter duration of surgery; less fluoroscopy frequency, intraoperative bleeding, and total drilling than in the conventional group (P < 0.05). Postoperative radiological follow‐up showed that all screws were in the safe area and no screw penetrated the cortex. All wounds healed by primary intention and no iatrogenic damage to the blood vessels, nerves, and organs occurred. Patients showed good tolerance to INFIX and reported no discomfort. The mean follow‐up duration was 5.4 months; the fractures were all healed, no loss of reduction occurred, and the mean Majeed score at the last follow‐up did not show any difference.

Conclusion

TiRobot‐assisted percutaneous screw placement combined with INFIX for the anterior and posterior pelvic ring injuries is accurate, safe, less invasive, and shows satisfactory efficacy, suggesting it is a better method for minimally invasive treatment of unstable pelvic ring fractures.

Posterior Malleolus Fractures in Trimalleolar Ankle Fractures: Malleolus versus Transyndesmal Fixation

BACKGROUND

In ankle fractures involving the posterior malleolus, the issue of which types of fractures require posterior malleolus fixation is still controversial. Recent studies have demonstrated that trimalleolar fractures adversely affect the functional outcomes in comparison to bimalleolar fractures of the lateral and medial malleolus. The purpose of this study was to assess the effects of posterior malleolus fixation on the functional and radiological outcomes.

MATERIALS AND METHODS

Reduction quality, development of posttraumatic ankle osteoarthritis, and functional outcomes in 49 consecutive trimalleolar ankle fractures were evaluated retrospectively in patients with and without posterior malleolus fixation. Group I consisted of 29 patients, in which posterior malleolar fracture was left untreated. Twenty patients in Group II, posterior malleolar fragment was fixed directly by screws alone or plate screw. Twenty-one of these 49 patients were male (43%). The mean age was 47 years (range 20-82 years).

RESULTS

The mean followup was 12 to 51 months with a mean of 15 months (range 12-51 months). Statistically significant differences were found between Group I and Group II in terms of ankle arthrosis. American Orthopaedic Foot and Ankle Society score was significantly lower in Group I compared to Groups II.

CONCLUSIONS

These results demonstrate that posterior malleolar fracture fixation is closely related to successful radiological and functional outcomes after trimalleolar fractures. Transyndesmal screw fixation may not be needed in the cases where the posterior malleolar fracture fixated. For these reasons, we recommend that all posterior malleolar fractures have to be fixed regardless of size.

A biomechanical comparison of proximal femoral nails and locking proximal anatomic femoral plates in femoral fracture fixation: A study on synthetic bones

BACKGROUND

The incidence of fractures in the trochanteric area has risen with the increasing numbers of elderly people with osteoporosis. Although dynamic hip screw fixation is the gold standard for the treatment of stable intertrochanteric femur fractures, treatment of unstable intertrochanteric femur fractures still remains controversial. Intramedullary devices such as Gamma nail or proximal femoral nail and proximal anatomic femur plates are in use for the treatment of intertrochanteric femur fractures. There are still many investigations to find the optimal implant to treat these fractures with minimum complications. For this reason, we aimed to perform a biomechanical comparison of the proximal femoral nail and the locking proximal anatomic femoral plate in the treatment of unstable intertrochanteric fractures.

MATERIALS AND METHODS

Twenty synthetic, third generation human femur models, obtained for this purpose, were divided into two groups of 10 bones each. Femurs were provided as a standard representation of AO/Orthopedic Trauma Associationtype 31-A2 unstable fractures. Two types of implantations were inserted: the proximal femoral intramedullary nail in the first group and the locking anatomic femoral plate in the second group. Axial load was applied to the fracture models through the femoral head using a material testing machine, and the biomechanical properties of the implant types were compared.

RESULT

Nail and plate models were locked distally at the same level. Axial steady load with a 5 mm/m velocity was applied through the mechanical axis of femur bone models. Axial loading in the proximal femoral intramedullary nail group was 1.78-fold greater compared to the plate group. All bones that had the plate applied were fractured in the portion containing the distal locking screw.

CONCLUSION

The proximal femoral intramedullary nail provides more stability and allows for earlier weight bearing than the locking plate when used for the treatment of unstable intertrochanteric fractures of the femur. Clinicians should be cautious for early weight bearing with locking plate for unstable intertrochanteric femur fractures.

Topical review: locking plate technology in foot and ankle surgery

The use of locking plate technology in foot and ankle surgery has increased over the last decade. Reported applications include fracture repair, deformity correction, and arthrodesis. There is limited evidence, however, to guide clinicians with regard to the appropriate and optimal use of this technology. This work aims to examine the current biomechanical and clinical evidence comparing locking construct technology to other forms of fixation in the field of foot and ankle surgery.

Treatment of the humeral shaft fractures--minimally invasive osteosynthesis with bridge plate versus conservative treatment with functional brace: study protocol for a randomised controlled trial

BACKGROUND

Humeral shaft fractures account for 1 to 3% of all fractures in adults and for 20% of all humeral fractures. Non-operative treatment is still the standard treatment of isolated humeral shaft fractures, although this method can present unsatisfactory results. Surgical treatment is reserved for specific conditions. Modern concepts of internal fixation of long bone shaft fractures advocate relative stabilisation techniques with no harm to fracture zone. Recently described, minimally invasive bridge plate osteosynthesis has been shown to be a secure technique with good results for treating humeral shaft fractures. There is no good quality evidence advocating which method is more effective. This randomised controlled trial will be performed to investigate the effectiveness of surgical treatment of humeral shaft fractures with bridge plating in comparison with conservative treatment with functional brace.

METHODS/DESIGN

This randomised clinical trial aims to include 110 patients with humeral shaft fractures who will be allocated after randomisation to one of the two groups: bridge plate or functional brace. Surgical treatment will be performed according to technique described by Livani and Belangero using a narrow DCP plate. Non-operative management will consist of a functional brace for 6 weeks or until fracture consolidation. All patients will be included in the same rehabilitation program and will be followed up for 1 year after intervention. The primary outcome will be the DASH score after 6 months of intervention. As secondary outcomes, we will assess SF-36 questionnaire, treatment complications, Constant score, pain (Visual Analogue Scale) and radiographs.

DISCUSSION

According to current evidence shown in a recent systematic review, this study is one of the first randomised controlled trials designed to compare two methods to treat humeral shaft fractures (functional brace and bridge plate surgery).

Interventions for the management of mandibular fractures

BACKGROUND

Fractures of the mandible (lower jaw) are a common occurrence and usually related to interpersonal violence or road traffic accidents. Mandibular fractures may be treated using open (surgical) and closed (non-surgical) techniques. Fracture sites are immobilized with intermaxillary fixation (IMF) or other external or internal devices (i.e. plates and screws) to allow bone healing. Various techniques have been used, however uncertainty exists with respect to the specific indications for each approach.

OBJECTIVES

The objective of this review is to provide reliable evidence of the effects of any interventions either open (surgical) or closed (non-surgical) that can be used in the management of mandibular fractures, excluding the condyles, in adult patients.

SEARCH METHODS

We searched the following electronic databases: the Cochrane Oral Health Group's Trials Register (to 28 February 2013), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2013, Issue 1), MEDLINE via OVID (1950 to 28 February 2013), EMBASE via OVID (1980 to 28 February 2013), metaRegister of Controlled Trials (to 7 April 2013), ClinicalTrials.gov (to 7 April 2013) and the WHO International Clinical Trials Registry Platform (to 7 April 2013). The reference lists of all trials identified were checked for further studies. There were no restrictions regarding language or date of publication.

SELECTION CRITERIA

Randomised controlled trials evaluating the management of mandibular fractures without condylar involvement. Any studies that compared different treatment approaches were included.

DATA COLLECTION AND ANALYSIS

At least two review authors independently assessed trial quality and extracted data. Results were to be expressed as random-effects models using mean differences for continuous outcomes and risk ratios for dichotomous outcomes with 95% confidence intervals. Heterogeneity was to be investigated to include both clinical and methodological factors.

MAIN RESULTS

Twelve studies, assessed as high (six) and unclear (six) risk of bias, comprising 689 participants (830 fractures), were included. Interventions examined different plate materials and morphology; use of one or two lag screws; microplate versus miniplate; early and delayed mobilization; eyelet wires versus Rapid IMF™ and the management of angle fractures with intraoral access alone or combined with a transbuccal approach. Patient-oriented outcomes were largely ignored and post-operative pain scores were inadequately reported. Unfortunately, only one or two trials with small sample sizes were conducted for each comparison and outcome. Our results and conclusions should therefore be interpreted with caution. We were able to pool the results for two comparisons assessing one outcome. Pooled data from two studies comparing two miniplates versus one miniplate revealed no significant difference in the risk of post-operative infection of surgical site (risk ratio (RR) 1.32, 95% CI 0.41 to 4.22, P = 0.64, I(2) = 0%). Similarly, no difference in post-operative infection between the use of two 3-dimensional (3D) and standard (2D) miniplates was determined (RR 1.26, 95% CI 0.19 to 8.13, P = 0.81, I(2) = 27%). The included studies involved a small number of participants with a low number of events.

AUTHORS' CONCLUSIONS

This review illustrates that there is currently inadequate evidence to support the effectiveness of a single approach in the management of mandibular fractures without condylar involvement. The lack of high quality evidence may be explained by clinical diversity, variability in assessment tools used and difficulty in grading outcomes with existing measurement tools. Until high level evidence is available, treatment decisions should continue to be based on the clinician's prior experience and the individual circumstances.

Pedicle screw fixation for traumatic fractures of the thoracic and lumbar spine

BACKGROUND

Spine fractures are common. The treatment of traumatic fractures of the thoracic and lumbar spine remains controversial but surgery involving pedicle screw fixation has become a popular option.

OBJECTIVES

To assess the effects (benefits and harms) of pedicle screw fixation for traumatic fractures of the thoracic and lumbar spine.

SEARCH METHODS

We searched the Cochrane Bone, Joint and Muscle Trauma Group Specialised Register (March 2011), the Cochrane Central Register of Controlled Trials (CENTRAL; The Cochrane Library, 2011 Issue 1), MEDLINE (1948 to March 2011), EMBASE (1980 to 2011 Week 11), the Chinese Biomedical Database (CBM Database) (1978 to March 2011), the WHO International Clinical Trials Registry Platform (March 2011), reference lists of articles and conference proceedings.

SELECTION CRITERIA

Randomised controlled trials (RCTs) and quasi-randomised controlled trials comparing pedicle screw fixation and other methods of surgical treatment, or different methods of pedicle screw fixation, for treating traumatic fractures of the thoracic and lumbar spine.

DATA COLLECTION AND ANALYSIS

Three review authors independently performed study selection, risk of bias assessment and data extraction. Limited meta-analysis was performed.

MAIN RESULTS

Pedicle screw fixation versus other methods of surgery that do not involve pedicle screw fixation was not looked at in any of the identified trials. Studies that were identified investigated different methods of pedicle fixation.Five randomised and three quasi-randomised controlled trials were included. All were at high or unclear risk of various biases, including selection, performance and detection bias. A total of 448 patients with thoracic and lumbar spine fractures were included in the review. Participants were restricted to individuals without neurological impairment in five trials. The mean ages of study populations of the eight trials ranged from 33 to 41 years, and participants had generally experienced traumatic injury. Mean follow-up for trial participants in the eight trials ranged from 28 to 72 months.Five comparisons were tested.Two trials compared short-segment instrumentation versus long-segment instrumentation. These studies found no significant differences between the two groups in self-reported function and quality of life at final follow-up. Aside from one participant, who sustained partial neurological deterioration that was resolved by further surgery (group not known), no neurological deterioration was noted in these trials.One trial comparing short-segment instrumentation with transpedicular bone grafting versus short-segment fixation alone found no significant difference between the two groups related to patient-perceived function and pain at final follow-up. All participants had normal findings on neurological examination at final follow-up.Two trials compared posterior instrumentation with fracture level screw incorporation ('including' group) versus posterior instrumentation alone ('bridging' group). Investigators reported no differences between the two groups in patient-reported function, quality of life, or pain at final follow-up. One trial confirmed that all participants had normal findings on neurological examination at final follow-up.One trial comparing monosegmental pedicle screw instrumentation versus short-segment pedicle instrumentation found no significant differences between the two groups in Oswestry Disability Index results or in pain scores at final follow-up. No neurological deterioration was reported.Three trials compared posterior instrumentation with fusion versus posterior instrumentation without fusion. Researchers found no differences between the two groups in function and quality of life or pain. No participants showed a decline in neurological status in any of the three trials, and no significant difference was reported between groups in the numbers whose status had improved at final follow-up. Two trials stated that patients in the fusion group frequently had donor site pain. Other reported complications included deep vein thrombosis and superficial infection.

AUTHORS' CONCLUSIONS

This review included only eight small trials and five different comparisons of methods of pedicle fixation in various participants while looking at a variety of outcomes at different time points. Overall, evidence is insufficient to inform the selection of different methods of pedicle screw fixation or the combined use of fusion. However, in the absence of robust evidence to support fusion, it is important to factor the risk of long-term donor site pain related to bone harvesting into the decision of whether to use this intervention. Further research involving high-quality randomised trials is needed.

Surgical interventions for treating acute fractures or non-union of the middle third of the clavicle

BACKGROUND

This review covers two conditions: acute clavicle fractures and non-union resulting from failed fracture healing. Clavicle (collarbone) fractures account for around 4% of all fractures. While treatment for these fractures is usually non-surgical, some types of clavicular fractures, as well as non-union of the middle third of the clavicle, are often treated surgically. This is an update of a Cochrane review first published in 2009.

OBJECTIVES

To evaluate the effects (benefits and harms) of different methods of surgical treatment for acute fracture or non-union of the middle third of the clavicle.

SEARCH METHODS

We searched the Cochrane Bone, Joint and Muscle Trauma Group Specialised Register (27 June 2014), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2014, Issue 5), MEDLINE (1966 to June week 3 2014), EMBASE (1988 to 2014 week 25), LILACS (1982 to 27 June 2014), trial registries and reference lists of articles. We applied no language or publication restrictions.

SELECTION CRITERIA

We considered randomised and quasi-randomised controlled trials evaluating any surgical intervention for treating people with fractures or non-union of the middle third of the clavicle. The primary outcomes were shoulder function or disability, pain and treatment failure (measured by the number of participants who had undergone or were being considered for a non-routine secondary surgical intervention for symptomatic non-union, malunion or other complications).

DATA COLLECTION AND ANALYSIS

Two review authors selected eligible trials, independently assessed risk of bias and cross-checked data. Where appropriate, we pooled results of comparable trials.

MAIN RESULTS

We included seven trials in this review with 398 participants. Four trials were new in this update.The four new trials (160 participants) compared intramedullary fixation with open reduction and internal fixation with plate for treating acute middle third clavicle fractures in adults. Low quality evidence from the four trials indicated that intramedullary fixation did not result in a clinically important improvement in upper arm function (despite a statistically significant difference in its favour: standardised mean difference 0.45, 95% confidence interval (CI) 0.08 to 0.81; 120 participants, three trials) at long term follow-up of six months or more. Very low quality evidence indicated little difference between intramedullary fixation and plate fixation in pain (one trial), treatment failure resulting in non-routine surgery (2/68 with intramedullary fixation vs. 3/65 with plate fixation; risk ratio 0.69, 95% CI 0.16 to 2.97, four trials) or time to clinical fracture consolidation (three trials). There was very low quality evidence of a lower incidence of participants with adverse events (mainly infection, poor cosmetic result and symptomatic hardware) in the intramedullary fixation group (18/68 with intramedullary fixation vs. 27/65 with plate fixation; RR 0.64, 95% CI 0.39 to 1.03) but the CI of the pooled results also included the small possibility of a lower incidence in the plate fixation group. None of the four trials reported on quality of life or return to previous activities. Evidence is pending from two ongoing trials, with planned recruitment of 245 participants, testing this comparison.There was low or very low quality evidence from three small trials, each testing a different comparison. The three trials had design features that carried a high risk of bias, potentially limiting the reliability of their findings. Low-contact dynamic compression plates appeared to be associated with significantly better upper-limb function throughout the year following surgery, earlier fracture union and return to work, and a reduced incidence of implant-associated symptoms when compared with a standard dynamic compression plate in 36 adults with symptomatic non-union of the middle third of the clavicle. One quasi-randomised trial (69 participants) compared Knowles pin versus a plate for treating middle third clavicle fractures or non-union. Knowles pins appeared to be associated with lower pain levels and use of postoperative analgesics and a reduced incidence of implant-associated symptoms. One study (133 participants) found that a three-dimensional technique for fixation with a reconstruction plate was associated with a significantly lower incidence of symptomatic delayed union than a standard superior position surgical approach. Evidence is pending from two ongoing trials, with planned recruitment of 130 participants, comparing anterior versus superior plates for acute fractures.

AUTHORS' CONCLUSIONS

There is very limited and low quality evidence available from randomised controlled trials regarding the effectiveness of different methods of surgical fixation of fractures and non-union of the middle third of the clavicle. The evidence from four ongoing trials is likely to inform practice for the comparisons of intramedullary versus plate fixation and anterior versus superior plates for acute fractures in a future update. Further randomised trials are warranted, but in order to optimise research effort, these should be preceded by research that aims to identify priority questions.

Surgical performance when inserting non-locking screws: a systematic review

Billions of screws are inserted by surgeons each year, making them the most commonly inserted implant. When using non-locking screws, insertion technique is decided by the surgeon, including how much to tighten each screw. The aims of this study were to assess, through a systematic review, the screw tightness and rate of material stripping produced by surgeons and the effect of different variables related to screw insertion.

Twelve studies were included, with 260 surgeons inserting a total of 2793 screws; an average of 11 screws each, although only 1510 screws have been inserted by 145 surgeons where tightness was measured – average tightness was 78±10% for cortical (n = 1079) and 80±6% for cancellous screw insertions (n = 431).

An average of 26% of all inserted screws irreparably damaged and stripped screw holes, reducing the construct pullout strength. Furthermore, awareness of bone stripping is very poor, meaning that screws must be considerably overtightened before a surgeon will typically detect it.

Variation between individual surgeons’ ability to optimally insert screws was seen, with some surgeons stripping more than 90% of samples and others hardly any. Contradictory findings were seen for the relationship between the tightness achieved and bone density.

The optimum tightness for screws remains unknown, thus subjectively chosen screw tightness, which varies greatly, remains without an established target to generate the best possible construct for any given situation. Work is needed to establish these targets, and to develop methods to accurately and repeatably achieve them.

Cite this article: EFORT Open Rev 2020;5:26-36. DOI: 10.1302/2058-5241.5.180066

Operative versus non-operative treatment of humeral shaft fractures: A systematic review

BACKGROUND

Humeral shaft fractures are common but debate still occurs as to whether these are best managed operatively or non-operatively. We sought to undertake a systematic review and meta-analysis of randomised and non-randomised studies to clarify the optimal treatment.

METHODS

We performed a search for all randomised and non-randomised comparative studies on humeral shaft fracture. We included only those with an operative and non-operative cohort in adult patients. We undertook a meta-analysis of the following outcome measures: nonunion, malunion, delayed union, iatrogenic nerve injury and infection. Non-operative management was with a functional brace.

RESULTS

Non-operative management resulted in a significantly higher nonunion rate of 17.6% compared to 6.3% with fixation. Operative management had a significantly higher iatrogenic nerve injury rate of 3.4% and infection rate of 3.7%. All nonunions within the included studies went on to union after plate fixation. There was no significant difference in delayed union or patient reported outcome measures. There was a significantly increased risk of malunion with non-operative treatment however this did not correlate with the outcome.

DISCUSSION

Our findings suggest that in the majority of cases, humeral shaft fractures can be managed with non-operative treatment, and any subsequent nonunion should be treated with plate fixation.

A new mini-invasive technique in treating pediatric diaphyseal forearm fractures by bioabsorbable elastic stable intramedullary nailing: a preliminary technical report

BACKGROUND AND AIM

Operative treatment is often indicated in unstable pediatric diaphyseal forearm fractures. Recently minimally invasive reduction and elastic stable intramedullary nailing have been of increasing interest, instead of open reduction and internal fixation with plates. There are several disadvantages of metallic intramedullary implants, such as soft-tissue irritation and a risk of disturbing later imaging. Thus, they are generally removed in later operations. We aimed to develop a new technique to stabilize pediatric forearm fractures by the bioabsorbable intramedullary nailing.

MATERIAL AND METHODS

We developed a new, two-stage mini-invasive surgical technique to stabilize the unstable diaphyseal fractures in children. The procedure is bioabsorbable elastic stable intramedullary nailing. Ultra-high-strength bioabsorbable intramedullary nails of poly(lactide-co-glycolide) were manufactured for our purpose. The material has been widely proven to be biocompatible and stable enough for fracture treatment as screws and pins. We have used the new technique in the unstable both-bone diaphyseal forearm fractures in children between the ages of 5 and 15 years. We report the technique and our clinical experience in the series of those three cases that have been followed up for at least 12 months. The present series has been randomized for the procedure instead for titanium elastic stable intramedullary nailing, and the series represents a part of ongoing randomized trial.

RESULTS

The reported cases operated by the new technique referred good union in the fractured bones and acceptable alignment in the follow-up. Removal of the implants was not required. No troubles with the procedure or implant per se were noticed, indicating good feasibility. One high-energy refracture occurred half year after the primary trauma. Traditional titanium implants were used to control the refracture.

CONCLUSIONS

We report our preliminary experience of a new surgical mini-invasive procedure to stabilize the unstable pediatric forearm shaft fractures by bioabsorbable elastic stable intramedullary nailing. Our clinical experience suggests that the procedure combined with long-arm casting is feasible in treating the pediatric forearm fractures. The technique may bring benefits to handling these challenging fractures. The disadvantages of metallic implants may be avoided. In addition, removal of the implant will not be required. There was one refracture in the series, but it was due to new high-energy trauma. According to our understanding, it was not related to the type of former osteosynthesis. However, ignoring the good preliminary experience, still we do not have results of the superiority of the procedure over traditional elastic stable intramedullary nailing. Our ongoing randomized multicenter study is aimed to determine its long-term outcome against the present golden standard. Nevertheless, due to encouraging preliminary results, we see it necessary to report the technique.

A Meta-Analysis for Postoperative Complications in Tibial Plafond Fracture: Open Reduction and Internal Fixation Versus Limited Internal Fixation Combined With External Fixator

The treatment of tibial plafond fractures is challenging to foot and ankle surgeons. Open reduction and internal fixation and limited internal fixation combined with an external fixator are 2 of the most commonly used methods of tibial plafond fracture repair. However, conclusions regarding the superior choice remain controversial. The present meta-analysis aimed to quantitatively compare the postoperative complications between open reduction and internal fixation and limited internal fixation combined with an external fixator for tibial plafond fractures. Nine studies with 498 fractures in 494 patients were included in the present study. The meta-analysis found no significant differences in bone healing complications (risk ratio [RR] 1.17, 95% confidence interval [CI] 0.68 to 2.01, p = .58], nonunion (RR 1.09, 95% CI 0.51 to 2.36, p = .82), malunion or delayed union (RR 1.24, 95% CI 0.57 to 2.69, p = .59), superficial (RR 1.56, 95% CI 0.43 to 5.61, p = .50) and deep (RR 1.89, 95% CI 0.62 to 5.80) infections, arthritis symptoms (RR 1.20, 95% CI 0.92 to 1.58, p = .18), or chronic osteomyelitis (RR 0.31, 95% CI 0.05 to 1.84, p = .20) between the 2 groups.

Surgical interventions for treating fractures of the olecranon in adults

BACKGROUND

Fractures of the olecranon (the bony tip of the elbow) account for approximately 1% of all upper extremity fractures. Surgical intervention is often required to restore elbow function. Two key methods of surgery are tension band wire fixation and plate fixation.

OBJECTIVES

To assess the effects (benefits and harms) of different surgical interventions in the treatment of olecranon fractures in adults.

SEARCH METHODS

We searched the Cochrane Bone, Joint and Muscle Trauma Group Specialised Register (22 September 2014), the Cochrane Central Register of Controlled Trials (CENTRAL, 2014, Issue 8), MEDLINE (1946 to September week 2 2014), EMBASE (1980 to 19 September 2014), trial registers, conference proceedings and reference lists of articles.

SELECTION CRITERIA

Randomised controlled trials (RCT) and quasi-RCTs that compared different surgical interventions for the treatment of olecranon fractures in adults.

DATA COLLECTION AND ANALYSIS

Two review authors independently performed study selection, risk of bias assessment and data extraction. The primary outcomes of this review were function, pain and adverse events.

MAIN RESULTS

We included six small trials involving 244 adults with olecranon fractures. Of these, four were RCTs and two were quasi-RCTs; both of were at high risk of selection bias. All six trials were at high risk of performance bias, reflecting lack of blinding, and four trials were at high risk of detection bias. The quality of the evidence for most outcomes was generally very low because of limitations in study design and implementation, and either imprecision of the results or inadequate outcome measures. Thus, we are very uncertain about the estimates of effect.One trial (41 participants) comparing plate fixation with standard tension band wiring provided very low quality evidence at 16 to 86 weeks' follow-up of a better clinical outcome after plate fixation (good outcome (little pain or loss of elbow motion): 19/22 versus 9/19, risk ratio (RR) 1.82 favouring plate fixation, 95% confidence interval (CI) 1.10 to 3.01). There was very low quality evidence of less symptomatic prominent metalwork after plate fixation (1/22 versus 8/19; RR 0.11, 95% CI 0.01 to 0.79). The results for other adverse effects (infection and delayed or non-union) were inconclusive. Evidence is pending from a newly (September 2014) completed trial (67 participants) making the same comparison.Four trials compared four different modified techniques of tension band wiring (i.e. additional intramedullary screw fixation, biodegradable pins, Netz pins and cable pin system) versus standard tension band wiring. There was very low quality evidence of little difference at six to 14 months in function assessed by a non-validated scoring tool from the addition of an intramedullary screw. However, there were fewer cases of metalwork prominence in the intramedullary screw group (1/15 versus 8/15; RR 2.00, 95% CI 1.15 to 3.49; one trial; 30 participants). There was very low quality evidence from one trial (25 participants) of little difference in subjectively or objectively assessed good outcome at a mean of 20 months between tension band wiring with biodegradable implants versus metal implants. There were no adverse events, either non-union or sinus or fluid accumulation, reported. All 10 participants in the metalwork group had an extra operation to remove their metalwork at one year. One trial, which did not report on function or pain, provided very low quality evidence of lower rates of metalwork for any reason or for symptoms after Netz pin tension band wiring compared with standard tension band wiring (11/21 with Netz pin versus 17/25 with standard tension band wiring; RR 0.77, 95% CI 0.47 to 1.26; 46 participants); this evidence also supports the possibility of higher rates of metalwork removal for Netz pins. Two intra-operative complications occurred in the Netz pin group. The fourth trial, which compared the cable pin system with standard procedure, found low quality evidence that cable pin improved functional outcome at a mean of 21 months (Mayo Elbow Performance Score (MEPS), range 0 to 100: best outcome: mean difference (MD) 7.89 favouring cable pin, 95% CI 3.14 to 12.64; one trial; 62 participants). It also found low quality evidence of fewer postoperative complications in the cable pin group (1/30 with cable pin system versus 7/32 standard tension band wiring; RR 0.15, 95% CI 0.02 to 1.17), although the evidence did not rule out the converse.One trial provided very low quality evidence of similar patient-reported function using the Disabilities of the Arm, Shoulder and Hand questionnaire (0 to 100: worst function) at two or more years after fixation using a novel olecranon memory connector (OMC) compared with locking plate fixation (MD -0.70 favouring OMC, 95% CI -4.20 to 2.80; 40 participants). The only adverse event was a superficial infection in the locking plate group.

AUTHORS' CONCLUSIONS

There is insufficient evidence to draw robust conclusions on the relative effects of the surgical interventions evaluated by the included trials. Further evidence, including patient-reported data, on the relative effects of plate versus tension band wiring is already pending from one recently completed RCT. Further RCTs, using good quality methods and reporting validated patient-reported measures of function, pain and activities of daily living at set follow-ups, are needed, including checking positive findings such as those relating to the use of an intramedullary screw and the cable pin system. Such trials should also include the systematic assessment of complications, further treatment including routine removal of metalwork and use of resources.

Infection after fracture osteosynthesis - Part I

Bone and surgical site infections after osteosynthesis are notoriously difficult to manage and pose a tremendous burden in fracture management. In this article, we use the term osteosynthesis-associated infection (OAI) to refer to this clinical entity. While relatively few surgically treated fractures become infected, it is challenging to perform a rapid diagnosis. Optimal management strategies are complex and highly customized to each scenario and take into consideration the status of fracture union, the presence of hardware and the degree of mechanical stability. At present, a high level of relevant evidence is unavailable; most findings presented in the literature are based on laboratory work and non-randomized clinical studies. We present this overview of OAI in two parts: an examination of recent literature concerning OAI pathogenesis, diagnosis and classification and a review of treatment options.

Current management of trimalleolar ankle fractures

A trimalleolar ankle fracture is considered unstable and treatment is generally performed operatively. Computed tomography is important for the operative planning by providing an elaborated view of the posterior malleolus.

Trimalleolar ankle fractures have a rising incidence in the last decade with up to 40 per 100,000 people per year. With a growing number of elderly patients, trimalleolar ankle injuries will become more relevant in the form of fragility fractures, posing a particular challenge for trauma surgeons.

In patients with osteoporotic trimalleolar ankle fractures and relevant concomitant conditions, further evidence is awaited to specify indications for open reduction and internal fixation or primary transfixation of the ankle joint.

In younger, more demanding patients, arthroscopic-assisted surgery might improve the outcome, but future research is required to identify patients who will benefit from assisted surgical care.

This review considers current scientific findings regarding all three malleoli to understand the complexity of trimalleolar ankle injuries and provide the reader with an overview of treatment strategies and research, as well as future perspectives.

Cite this article: EFORT Open Rev 2021;6:692-703. DOI: 10.1302/2058-5241.6.200138

Biomechanical Assessment of the Validity of Sheep as a Preclinical Model for Testing Mandibular Fracture Fixation Devices

Mandibular fracture fixation and reconstruction are usually performed using titanium plates and screws, however, there is a need to improve current fixation techniques. Animal models represent an important step for the testing of new designs and materials. However, the validity of those preclinical models in terms of implant biomechanics remains largely unknown. In this study, we investigate the biomechanics of the sheep mandible as a preclinical model for testing the mechanical strength of fixation devices and the biomechanical environment induced on mandibular fractures. We aimed to assess the comparability of the biomechanical conditions in the sheep mandible as a preclinical model for human applications of fracture fixation devices and empower analyses of the effect of such defined mechanical conditions on bone healing outcome. We developed 3D finite element models of the human and sheep mandibles simulating physiological muscular loads and three different clenching tasks (intercuspal, incisal, and unilateral). Furthermore, we simulated fractures in the human mandibular body, sheep mandibular body, and sheep mandibular diastema fixated with clinically used titanium miniplates and screws. We compared, at the power stroke of mastication, the biomechanical environment (1) in the healthy mandibular body and (2) at the fracture sites, and (3) the mechanical solicitation of the implants as well as the mechanical conditions for bone healing in such cases. In the healthy mandibles, the sheep mandibular body showed lower mechanical strains compared to the human mandibular body. In the fractured mandibles, strains within a fracture gap in sheep were generally not comparable to humans, while similar or lower mechanical solicitation of the fixation devices was found between the human mandibular body fracture and the sheep mandibular diastema fracture scenarios. We, therefore, conclude that the mechanical environments of mandibular fractures in humans and sheep differ and our analyses suggest that the sheep mandibular bone should be carefully re-considered as a model system to study the effect of fixation devices on the healing outcome. In our analyses, the sheep mandibular diastema showed similar mechanical conditions for fracture fixation devices to those in humans.

Lessons learned from volar plate fixation of scaphoid fracture nonunions

Treating scaphoid nonunions presents difficulties particularly when there is bone loss, significant humpback deformity or avascular necrosis. We describe a new type of fixation with a volar scaphoid plate that adds to the methods of internal fixation that are available for the treatment of recalcitrant scaphoid nonunions. We will also discuss 'lessons learned' from a cases series. The case series includes 20 consecutive patients treated with volar buttress plating and a pedicled vascularized bone graft from the ipsilateral volar distal radius. There was clinical and radiographic evidence of union in 18 of 20 patients, 13 of which were verified by computed tomographic scan. The range of motion was improved in all patients post-operatively. Four patients with radiographic union experienced intermittent clicking with maximal wrist flexion, believed to be due to the impingement of the plate on the volar aspect of the radioscaphoid articulation and underwent removal at approximately 1 year after the index procedure. Volar scaphoid plating is a useful alternative to headless scaphoid screw fixation in the treatment of unstable scaphoid waist fractures and nonunions.

LEVEL OF EVIDENCE

IV.

Axillary nerve lesions after open reduction and internal fixation of proximal humeral fractures through an extended lateral deltoid-split approach: electrophysiological findings

BACKGROUND

Axillary nerve injuries after shoulder surgery are rare. In most studies, the frequency of injury is usually determined using clinical examinations, but results from intraoperative neuromonitoring studies have revealed higher than expected rates. Few studies have investigated this topic. Our aim was to determine the frequency of axillary nerve lesions after open reduction and internal fixation of proximal humeral fractures by using electrophysiological assessments and to provide a review of the relevant literature.

METHODS

This was a retrospective cohort study of 76 consecutive patients who received open reduction and internal fixation of a proximal humeral fracture using a locking plate through a deltoid-splitting approach. We performed a clinical and electrophysiological examination at a minimum follow-up time of 12 months. Functional results were assessed according to the Constant-Murley and Disabilities of the Arm, Shoulder and Hand scores. Electrophysiological examinations comprised electromyography, electroneurography, and motor and somatosensory evoked potentials. The main outcome was the frequency of axillary nerve lesions.

RESULTS

Forty patients were monitored for an average of 28 months. The mean raw Constant-Murley score was 61 points, the age- and gender-adjusted score was 71%, and the mean Disabilities of the Arm, Shoulder and Hand score was 33 points. Neurapraxia occurred in 1 patient, axonotmesis with incomplete reinnervation occurred in 3, and complete reinnervation occurred in 3. The latter group was classified as having a temporary axillary nerve lesion.

CONCLUSIONS

The 10% rate of permanent axillary nerve lesions in our cohort is higher than expected based on the clinical examination. Electrophysiological assessment is therefore more appropriate to detect axillary nerve injuries.