Effect of an ultrasonic device on temperatures generated in bone and on bone-cement structure

Cement removal during revision arthroplasty can be a tedious, time-consuming process. The usual methods of removing cement include high-speed drills, chisels, saws and reamers, which are often associated with fracture and/or perforation of the femoral shaft. Ultrasound has been used in dentistry to remove plaque and in ophthalmology to remove cataracts and is now applied to cement removal in orthopaedic surgery. There is little data available on the effect of ultrasound on temperatures generated in bone and on its effects on the structure of bone-cement. A cement mantle was constructed in the intramedullary canal in each of six 10 cm lengths of human cadaver femora. A temperature probe was then inserted into predrilled holes and temperatures generated by the ultrasonic device were recorded under a variety of conditions. In addition, a cement cylinder was microscopically evaluated after an ultrasonic tool had been inserted. Temperatures generated by the ultrasonic tool in cadaver bone were no higher than previously reported temperatures of 140°C generated by high-speed drills. Furthermore, temperatures at the bone-cement interface never exceeded 60°C when saline irrigation was used in conjunction with the ultrasonic tools, and were below 40°C 1 minute after deactivation of the device. Microscopic examination shows that ultrasound produced local changes in the structure of bone-cement converting it from a microscopically spherical interlocked material to one that appears homogeneous and granular.     

Extensile approach to the anterolateral surface of the humerus and the radial nerve

A proposed approach to the anterolateral surface of the humeral shaft that would allow for exploration of the radial nerve was studied in 30 cadaver arms. The incision starts proximally along the posterior border of the deltoid muscle and extends anteriorly and distally over the lateral border of the biceps muscle. A deep dissection is made in the internervous plane between the deltoid and the triceps muscles proximally and between the longitudinally split fibers of the brachialis muscle distally. The approach provides access to the anterolateral surface of the humerus up to the level of the axillary nerve and the posterior circumflex humeral vessels. The insertion of the deltoid muscle into the anterior border of the humerus is preserved and the radial nerve is protected by the triceps muscle proximally and by the retracted lateral portion of the brachialis muscle distally. The entire course of the radial nerve in the arm can be exposed. Proximally, the radial nerve can be exposed by elevating the lateral head of the triceps muscle from the humerus. Distally, the radial nerve can be exposed between the brachioradialis and the brachialis muscles. A plate can be applied on the anterolateral surface of the humerus without having to elevate the firmly attached anterior deltoid insertion.     

New technique for humerus shaft fracture retrograde intramedullary nailing

Humeral shaft fracture intramedullary nailing is less invasive than plates and screws. Antegrade technique has postoperative shoulder pain, increased rehab time, and frequent reoperation for rod removal. Published retrograde technique is not collinear with the shaft, has insertion site fractures (5% to 15%), and radial nerve palsies (5%). Our retrograde technique is collinear with the humerus shaft, simpler, and decreases operative fracture risk. The supine patient's elbow is fully flexed. A guide pin is inserted through the triceps tendon to the olecranon fossa roof, aligned with the humerus shaft, and drilled thought the cortex followed by the 6.5 mm cannulated drill through a small triceps splitting incision. The guide pin is passed along the humerus shaft and across the fracture. A small incision is made to identify and protect the radial nerve during reduction, reaming, and rod insertion. Flexible reamers are used and the nail placed and locked at least distally to prevent distal migration. An institutional review broad approved retrospective review of Louisiana State University Health Sciences Center adult humeral shaft fractures with retrograde technique from 1999 to January of 2009 was carried out. Sixteen patients were treated without perioperative fracture or nerve palsy.     

Surgical exposures of the humerus

The neurovascular and muscular anatomy about the humerus precludes the use of a truly "safe" fully extensile approach. Working around a spiraling radial nerve at the posterior midshaft requires either a transmuscular dissection or a triceps-avoiding paramuscular technique. To gain maximal exposure, the radial nerve must be mobilized at the spiral groove. For exposure of only the proximal humeral shaft, many surgeons prefer the anterolateral approach because it uses the internervous plane between the axillary and deltoid nerves proximally and the radial and musculocutaneous nerves distally. Proximally, the deltopectoral approach to the shoulder continues to be the most widely used. However, the lateral deltoid-splitting approach is a viable, less invasive approach for both rotator cuff repair and fixation of valgus-impacted proximal humeral fractures. Distally, intra-articular exposure is dependent on triceps mobilization, either by olecranon osteotomy or triceps release; this exposure can be coupled with either a triceps-splitting or a paratricipital approach for proximal extension.     

Revision total elbow replacement

The range of general and specific adverse event in total elbow arthroplasty is similar in principle and practice to all other revision prosthetic arthroplasty but with three particular challenges: loss of humeral and ulnar bone stock; insufficiency of the extensor ‘mechanism’; and the management of the ulnar nerve. Total elbow replacement is presently performed for the management of complex non-reconstructable distal humeral fractures in osteoporotic bone, for post-traumatic arthropathy, and for medically managed inflammatory arthritides in which metaphyseal bone architecture is often preserved while the articular surface is degenerate. In all these conditions the patient often presents for revision total elbow arthroplasty with relevant co-morbidities and relevant musculoskeletal dysfunction (for example: ipsilateral shoulder, wrist, thumb or hand dysfunction).Infection is a universal concern for revision arthroplasty but where the soft tissue ‘envelope’ is compromised and already limited, as in the proximal forearm, it is difficult to eradicate, particularly in immunocompromised patients.Bone loss compromises subsequent implantation of a revision prosthesis, while failure to restore the working lengths of the humerus and ulna reduces the strength of the flexor and extensor compartment muscles for elbow motion.Failure to restore the continuity of the triceps aponeurosis - antebrachial fascia and triceps medial head-olecranon components of the extensor ‘mechanism’ also compromises extensor power. Prior triceps-dividing surgical approaches will determine the elasticity, and therefore pliability, of the extensor ‘mechanism’: this will have a role in determining how much gain in length of the humeral side can be safely achieved.The ulnar nerve, and its management during elbow arthroplasty, is a source of frequent concern, particularly for revision of an elbow arthroplasty undertaken for distal non-reconstructable humeral articular fractures or post-traumatic arthropathy, in which the position of the ulnar nerve is never anatomic. For these reasons revision total elbow replacement (RTER) is challenging: it requires experience with surgical exposures of the elbow including the major nerve trunks, familiarity with the restoration of bone stock, a range of prostheses and techniques for prosthetic implantation, the ability to achieve adequate soft tissue cover and primary closure, and a logical approach to individualised rehabilitation.     

Constrained arthroplasty: its use and misuse

Constrained arthroplasty is occasionally needed to salvage a destroyed glenohumeral joint when the rotator cuff is nonfunctioning and when an unconstrained prosthesis will not suffice. There is a high failure rate because of the severe forces between such a device and the contiguous bone. Accordingly, it is essential to know the limitations of constrained arthroplasty and when it should be avoided. For example, when the bone of the glenoid vault is highly demineralized or deficient or if there is a history of seizure disorder or alcoholism, use of such a device is contraindicated. Postoperatively, excessive force and extremes of motion should also be avoided during the rehabilitation program to avoid bone fracture or dislocation of the prosthesis. Various complications have been observed with constrained arthroplasty, including dislocation, bone fracture, pullout of the glenoid, infection, radial nerve injury after extrusion of bone cement through the humeral cortex when the cement has been pressurized, and screw breakage in a relative small number of cases after metal fatigue and loosening of the glenoid component. When the glenoid component has pulled away from the glenoid vault, it may be necessary to remove this component; the humeral head may be fitted with a bipolar 40- to 44-mm acetabular component, thereby allowing at least preservation, if not the active function of the shoulder contour.     

The cemented humerus and non-cemented glenoid: The optimal hybrid solution for total shoulder arthroplasty

Hybrid fixation of total joint arthroplasty has been recognized as an accepted form of surgical approach in multiple joints. Principles of implant fixation should focus on durability and on providing secure long-term function. To date, there is no conclusive evidence that pressed-fit humeral stem fixation has an advantage over well-secured cemented humeral fixation. Although revision may require cement removal, a well-fixed bone—ingrowth implant may require slatting and osteotomy of the humerus. On the contrary, need for revision in arthroplasty due to inadequate implant fixation has almost universally revolved around the failure of cement fixation and loosening of the glenoid component. A case will be made based on 30 years of experience of a surgeon performing total shoulder arthroplasty using secure modern cement-fixation techniques of humeral components. More recently, over the past 10 years an extremely high rate of durable secure glenoid implant fixation has been achieved using press-fit tantalum porous anchorage of polyethylene glenoid components. This has resulted in no cases of loosening of glenoid fixation and only one case of glenoid component fracture with greater than 95% survivorship over a 10-year period. A combination of well-cemented humeral stem and trabecular metal anchorage of the glenoid has provided durable and long-lasting function in primary total shoulder arthroplasty.     

Ultrasound-guided block of the axillary nerve: a volunteer study of a new method

Background: Interscalene brachial plexus block (IBPB) is the gold standard for perioperative pain management in shoulder surgery. However, a more distal technique would be desirable to avoid the side effects and potential serious complications of IBPB. Therefore, the aim of the present study was to develop and describe a new method to perform an ultrasound‐guided specific axillary nerve block. Methods: After initial investigations, 12 healthy volunteers were included. We performed an in‐line ultrasound‐guided specific axillary nerve block by injecting 8 ml local anesthetic (lidocaine 20 mg/ml) after placing the tip of a nerve stimulation needle cranial to the posterior circumflex humeral artery in the neurovascular space bordered by the teres minor muscle, the deltoid muscle, the triceps muscle and the shaft of the humerus. Needle placement was aided by simultaneous nerve stimulation. We assessed sensory (pinprick and cold stimulation) and motor (active resistive force) block of the axillary nerve before, 15, 30, 60, 90 and 120 min after performing the block and every 30 min until termination of the block. Results: All 12 volunteers demonstrated sensory block of the axillary nerve and 10 volunteers demonstrated complete motor block. Even though it was difficult to directly visualize the axillary nerve, the block was easy to perform with easily recognizable ultrasonographic landmarks. Block duration was approximately 120 min. Conclusions: We describe a new ultrasound‐guided technique to specifically block the axillary nerve. The potential clinical role of this new block remains to be determined.     

肱骨逆行带锁髓内钉治疗肱骨干骨折体会

目的 用逆行带锁髓内钉治疗肱骨干骨折.方法 我院采用肱骨逆行带锁髓内钉治疗肱骨干骨折26例,男15例,女11例;年龄19～56岁,平均年龄32岁.结果 骨折固定满意,未发生桡神经损伤.结论 用逆行带锁髓内钉治疗肱骨干骨折,可有效避免医源性桡神经损伤,值得推广.     

Zemententfernung mit Ultraschall bei Revisionen von Hüfttotalprothesen

Bone cement (polymethylmethacrylate, PMMA) removal during revision hip arthroplasty can be a tedious, time-consuming process. The usual methods of removing cement include high-speed drills, chisels, saws, and reamers, which are often associated with fracture or perforation of the femoral shaft. An alternative very promising method is cement removal with ultrasound. We present an ultrasonic device for rapid cement removal with minimum risk of trauma to the fragile femoral bone. The technique of cement removal with ultrasound is described and problems and risks are addressed.     

Safe removal of massive intrapelvic cement using ultrasonic instruments

The extraction of massive intrapelvic deposits of cement in revision total hip arthroplasty presents the surgeon with a philosophical dilemma and a technical challenge. The cement is difficult to remove because of the disparity between the size of the cement mass and the defect in the acetabulum. In addition, the cement mass lies close to major intrapelvic organs, and the use of force applied with sharp cement-removing instruments poses a danger to these structures. We report on the ultrasonic technique of cement removal used to extract a massive intrapelvic cement deposit safely.     

Postoperative radial nerve palsy in humeral shaft nonunion reconstruction: Can the lateral paratricipital approach prevent this common complication?

BackgroundPostoperative radial nerve palsy (RNP) is a well-known complication of nonunion reconstruction of the humerus. The purpose of the current study is to determine if the surgical approach for nonunion reconstruction of the humerus influences the rate of postoperative radial nerve palsy.MethodsA retrospective case-control study of all humeral shaft and extraarticular distal humerus nonunion reconstructions performed between January 1, 2004, and August 31, 2021, was conducted. Patients included were over 18 years of age, had a non-pathologic humerus fracture nonunion and had intact radial nerve function prior to nonunion reconstruction. Exclusion criteria consisted of nonunions involving the proximal humerus, intraarticular fractures, and reconstructive treatment procedures with either intramedullary nail or external fixation methods. Perioperative variables were recorded and analyzed in regard to the development of postoperative RNP. A subgroup analysis was performed to assess the interaction of significant variables on the development of postoperative RNP.ResultsThe overall rate of postoperative RNP in this series was 6/53 (11%). However, no cases of postoperative radial nerve palsy were observed in patients who underwent nonunion reconstruction with a lateral paratricipital approach. A new RNP was seen in 4/9 (44%) of those patients who underwent a triceps splitting approach, which was significantly higher than those utilizing either an anterolateral approach (2/28, 7%) or a lateral paratricipital approach (0/16, 0%, p = 0.007).Discussion and conclusionOur data suggests that the lateral paratricipital exposure decreases the risk of radial nerve injury with nonunion reconstruction of the humerus. The lateral paratricipital exposure offers the benefit of radial nerve exploration, decompression, neurolysis and protection prior to fracture manipulation and instrumentation. This study shows conventional approaches may predispose patients to a high rate of postoperative RNP, similar to that in the literature.     

Ultrasonic technology in revision joint arthroplasty.

The development of ultrasonically driven tools for revision joint arthroplasty is presented. The data represent seven-years' experience and include information from laboratory investigation and clinical experience from 20 surgical cases. Whole bone torsional strength studies reveal no decrease in strength parameters after the removal of cement ultrasonically. Comparison studies demonstrate that ultrasonic tools allow more rapid completion of cement and prosthesis removal than traditional manual tools. Histologic studies using an in vivo canine model demonstrate no deleterious effects to endosteal bone where cement had been removed by ultrasound. Clinical studies indicate that the use of ultrasound facilitates the surgery and causes no cortical perforations; the creation of cortical windows was not necessary in all cases. Ultrasound is safe and efficacious in cement and prosthesis removal during revision surgery.     

Somatosensory evoked potential monitoring during closed humeral nailing: a preliminary report

OBJECTIVES: To assess the role of intraoperative somatosensory evoked potential (SSEP) monitoring of the radial and median nerves in preventing iatrogenic nerve injury during closed, locked intramedullary (IM) nailing of the humerus. DESIGN: Prospective clinical study. SETTING: Pacific Northwest Level One trauma center and Southern California military medical center. PATIENTS: Thirteen patients with indications for surgical stabilization of fractures of the humeral diaphysis and either unknown neurologic status of the affected limb or anticipated difficult reduction maneuvers due to fracture complexity or displacement. INTERVENTION: Closed, antegrade or retrograde locked IM nailing of the humerus was attempted while intraoperative monitoring of the radial and median nerves with SSEP was performed. MAIN OUTCOME MEASUREMENTS: Intraoperative radial and median nerve SSEP changes during closed fracture manipulation, guide rod insertion, reaming, and humeral nail placement. RESULTS: Baseline recordings were obtained in twelve of thirteen patients for both the radial and median nerves. An absence of radial nerve signal in one patient with a closed head injury prompted an open procedure, revealing entrapment of the radial nerve in the fracture. Intraoperative SSEP changes were observed in two of the twelve remaining patients during fracture manipulation and distal interlocking. The signal amplitude returned after discontinuation of manipulation and traction, and alteration of the interlocking maneuver. No neurologic deficits were noted in these two patients. CONCLUSIONS: Intraoperative radial nerve SSEP monitoring appears to reliably reflect the status of the radial nerve in those patients with a humerus fracture. In three of eleven patients, intraoperative signal changes prompted a change in surgical plan. In no patient did there appear to be evidence of iatrogenic nerve injury.     

A review of humeral stem removal during revision shoulder arthroplasty

Despite the overwhelming clinical success of shoulder arthroplasty, several situations may arise that necessitate revision arthroplasty. This often requires removal of the humeral component. Extraction of a humeral prosthesis is a technically demanding procedure, which requires an understanding of the indications for humeral component explantation, careful preoperative planning, knowledge of the humeral component to be removed, a grasp of several different methods of stem removal, and the tools required. Cement extraction often poses substantial technical challenges and requires further specialized instruments. Surgeons should be prepared to manage specific complications that may arise such as canal perforation and humerus fracture.     

Humeral cemented revision: Techniques for safe extraction

Removing a well-fixed humeral component in revision shoulder arthroplasty can present a difficult challenge. Intraoperative complications including iatrogenic fracture, humeral perforation, segmental bone loss, nerve and soft tissue injury can occur. These complications can occur with both cemented and press-fitted stems and can lead to increased morbidity and decreased functional outcomes. Complete removal of the cement mantle and cement restrictor, when necessary, can present even further challenges. Several extraction techniques have been described that can help minimize complications and enable safe, complete component extraction.     

Five- to thirteen-year follow-up of the GSB III total elbow arthroplasty

Between 1988 and 1995, the senior author performed total elbow arthroplasty in 28 elbows (23 patients) with the GSB III prosthesis. At the most recent follow-up, 7 patients had died (9 elbows) and 1 had the implant removed because of a deep infection. The remaining 18 elbows (15 patients) were available for clinical and radiographic review at a mean period of 7.6 years (range, 5.5-11.9 years). All 15 patients were satisfied with the results of their elbow replacement, with a mean Mayo elbow performance score of 91 (range, 75-100). The mean flexion/extension and supination/pronation arcs improved by 33 degrees and 67 degrees, respectively. Radiographic follow-up demonstrated progressive loosening in only 1 patient and no progressive loosening in those with an adequate cement technique. Mild or moderate lysis of the distal humeral or proximal ulnar components was noted in 10 elbows, and severe lysis of the distal humerus was seen in 1. Of the patients, 6 (21%) had mild complications: triceps avulsions in 3, superficial wound infections in 2, and an undisplaced fracture of the distal humeral medial condyle in 1. In 4 patients (14%) complications developed requiring reoperation, including exchange of the polyethylene bushing because of wear, debridement of synovitis, resection arthroplasty for deep infection, and exploration of an ulnar nerve palsy. In 2 additional patients (7%), persistent ulnar nerve paresthesias developed postoperatively. Of the 28 elbow replacements performed with the GSB III prosthesis, only 1 required revision because of loosening at a mean follow-up of 7.6 years. The results of this series of GSB III elbow replacements in patients with rheumatoid arthritis demonstrate reasonable survivorship of this prosthesis.     

肘关节后侧肱三头肌-肘肌瓣入路治疗肱骨远端骨折

目的探讨自行设计的肱三头肌-肘肌瓣入路治疗肱骨远端骨折效果。方法采用自行设计的肱三头肌-肘肌瓣入路对57例C型(AO分类)肱骨远端骨折患者进行切开复位内固定治疗。结果患者均获得随访,时间5～26个月,57例骨折均获骨性愈合。按Jupiter肘关节功能评分:优41例,良12例,中3例,差1例(伤前存在肘关节畸形),优良率为92.3%。无切口皮肤坏死、深部感染、肱三头肌萎缩、骨化性肌炎、及骨不愈合发生。结论肱三头肌-肘肌瓣入路是治疗肱骨远端骨折的理想入路,可取得良好的肘关节和肱骨远端显露,内固定安放方便,术后可早期功能锻炼,临床效果好。     

Revision total elbow arthroplasty for prosthetic fractures

BACKGROUND: Fractures of total elbow arthroplasty components are uncommon, and the literature provides little guidance regarding the management and outcomes of treatment of these complications. The goal of this report was to investigate the prevalence and management of fractures of ulnar and humeral components following total elbow arthroplasty and to review our experience with cement-within-cement reconstruction for revision following such fractures. METHODS: Between 1979 and 2003, twenty-four patients with a total of twenty-seven fractured total elbow arthroplasty components (seventeen ulnar and ten humeral) of different designs presented to our institution. Twenty-six implants underwent subsequent revision elbow arthroplasty at our institution. Fourteen of those revisions were done with a cement-within-cement technique, and twelve, with traditional methods. Twenty-one patients (twenty-three implants) were available for final follow-up, and data that had been acquired prospectively and entered into the institutional arthroplasty database were reviewed retrospectively. At the time of final follow-up, the Mayo Elbow Performance Score (MEPS) was calculated and preoperative, postoperative, and most recent radiographs were examined for bone loss, bushing wear, and integrity of the bone-cement interface. RESULTS: The prevalences of humeral and ulnar component fracture following primary total elbow arthroplasties performed at our institution were 0.65% and 1.2%, respectively. At a mean of 5.1 years following revisions for those fractures, the MEPS was excellent for eight patients, good for five, fair for six, and poor for two. The average MEPS was 82 points following the revision total elbow arthroplasties done with the cement-within-cement technique and 78 points following the revisions done with the traditional method of cement removal and insertion of a revision component. Complications included seven intraoperative cortical perforations; five nerve injuries, two of which were permanent; three triceps avulsions; and one deep infection. CONCLUSIONS: Implant fractures following total elbow arthroplasty are uncommon. They occur for several reasons, such as notch sensitivity, component design, and high stresses due to bone deficiency. Revision techniques, such as cement-within-cement reimplantation, are reliable for relieving pain and restoring function; however, the rate and spectrum of complications are a cause for concern. LEVEL OF EVIDENCE: Therapeutic Level IV.     

Danger zone for locking screw placement in minimally invasive plate osteosynthesis (MIPO) of humeral shaft fractures: A cadaveric study

Several recent reports have described the minimally invasive plate osteosynthesis (MIPO) technique in the treatment of humeral shaft fractures by the anterior approach. The purpose of this study is to identify the danger zone for locking screw placement to avoid musculocutaneous nerve injury in the anterior compartment and radial nerve injury in the posterior compartment of the humerus relative to the humeral length. Eighteen arms of fresh cadavers were fixed with 10-hole locking compression plate (LCP) by anterior approach using the MIPO technique. Two locking screws on each end were fixed by the open technique; the rest of the screws were inserted percutaneously. The arms were dissected both anterior and posterior to identify musculocutaneous and radial nerve injuries. Humeral length with a simple palpable bony landmark was measured from the posterior tip of the acromion process to the lateral epicondyle. Damage or direct contact of the locking screws to the musculocutaneous or radial nerve was recorded, and the distance between the screws and the radial nerve was measured.The average humeral length was 29.71 cm (99% confidence interval (CI): 28.54-30.86 cm). The danger zone for the musculocutaneous nerve averaged 18.37% (99% CI: 17.06-19.60) to 42.67% (99% CI: 42.33-43.03) of the humeral length from the lateral epicondyle. The danger zone for the radial nerve averaged 36.35% (99% CI: 35.81-37.07) to 59.20% (99% CI: 59.00-59.46) of the humeral length, and the most dangerous screws that penetrated or touched the radial nerve lay 47.22% (99% CI: 45.27-49.17) to 53.21% (99% CI: 51.16-55.33) of the humeral length from the lateral epicondyle. An anteroposterior locking screw placed percutaneously endangered the musculocutaneous and radial nerves.From this cadaveric study, the danger zone for the musculocutaneous and radial nerves could be determined as a percentage of the humeral length. Since the zone with radial nerve injuries shows a large variation, this procedure should only be done by experienced surgeons.