Analysis of tardy ulnar nerve palsy associated with cubitus varus deformity after a supracondylar fracture of the humerus: a report of four cases

Association of Clinical Findings With Complications in the Cubitus Varus Deformity After Supracondylar Fracture

INTRODUCTION

Cubitus varus deformity is primarily a cosmetic complaint that causes some early and late complications. However, no studies have reported the cubitus varus deformity regarding the frequency of complications, relationship to the degree of deformity, and period from the occurrence of the initial injury.

METHODS

Overall, 83 patients with cubitus varus deformity were examined. The differences in the humerus-elbow-wrist angle (∆HEW-A), tilting angle (∆TA), and internal rotation angle (∆IRA) between the affected and normal sides were measured to determine varus and extension and internal rotation deformity. The period from the occurrence of the initial injury to the evaluation date was also investigated. Multivariate logistic regression analysis was conducted to identify the explanatory variables (period, ∆HEW-A, ∆TA, and ∆IRA) independently associated with complication events. Receiver-operating characteristic curve analysis was also conducted to predict the risk of events.

RESULTS

∆HEW-A was independently associated with the risk of cosmetic complaint (odds ratio [OR], 1.171; 95% confidence interval [95% CI], 1.056 to 1.336) and instability (OR, 1.111; 95% CI, 1.028 to 1.200). ∆TA was independently associated with the risk of limited elbow motion (OR, 1.176; 95% CI, 1.077 to 1.285) and sports disability (OR, 0.892; 95% CI, 0.836 to 0.952). The period from the occurrence of the initial injury was independently associated with risk of pain (OR, 1.063; 95% CI, 1.019 to 1.108), ulnar nerve neuropathy (OR, 1.065; 95% CI, 1.011 to 1.125), and osteoarthritis (OR, 1.188; 95% CI, 1.098 to 1.286). The receiver-operating characteristic curve analysis revealed the optimal cutoffs of 20° and 27° for ∆HEW-A to predict cosmetic complaint and instability; of 25° for ∆TA to predict limited elbow motion; and of 8.8, 8.0, and 16.0 years for the period to predict pain, ulnar nerve neuropathy, and osteoarthritis, respectively.

DISCUSSION

The treatment of cubitus varus deformity should be determined because a residual deformity >20° of varus and 25° of extension could develop risk of complications over time.

Posttraumatic Cubitus Varus: Respect the Columns

Posttraumatic cubitus varus is a multiplanar deformity that results from an improperly reduced supracondylar humerus fracture. The prevention of posttraumatic cubitus varus hinges on the stable restoration of all 3 columns of the distal humerus while avoiding malrotation. The collapse of any column leads to varying degrees of deformity in the coronal, sagittal, and/or axial plane. The purpose of this article is to explain the pattern of the deformity and use this to summarize preventative tactics for avoiding its described sequelae. We also summarize, illustrate, and present case examples for the various osteotomies used to correct the deformity, and speculate future directions.

Computer aided multiplanar osteotomy using patient specific instrumentation to treat cubitus varus in children

Cubitus varus deformity is a common complication of supracondylar fractures in children. Anatomic correction is the key to obtaining good functional results and avoiding later symptomatic degradation. Different techniques have been described, mainly lateral closing wedge osteotomy. A medial opening wedge osteotomy seems more intuitive, allowing an anatomic reduction, but it is technically challenging. Two-plane radiographs are too simplistic to appreciate the 3D deformity. With medical imaging and image processing advances, three-dimensional (3D) virtual models of a patient's anatomy can be generated. Rapid 3D printing has allowed virtual simulations of surgical corrections to be transferred to real-world applications in the operating room, allowing more precise and accurate surgery with better 3D corrections. 3D computer modeling with the development of customized drilling and cutting guides allows complex medial opening wedge osteotomy for correction of cubitus varus deformity in immature children with best-fit plate synthesis. LEVEL OF EVIDENCE: IV.

Guided Growth for the Treatment of Cubitus Varus in Children: Medium- to Long-Term Results

Correction of cubitus varus is commonly attempted through supracondylar humeral osteotomy. We hypothesized that lateral distal humeral hemiepiphysiodesis (LDHH) could be used to gradually correct this deformity in children. We conducted a retrospective study including all patients who underwent LDHH with the eight-Plate system between 2008 and 2018, with a minimum 4-year follow-up. We collected demographic, fracture-related, pre- and postoperative clinical (carrying angle (CA), ROM), and radiological data (humeral-ulnar angle (HUA), Baumann angle (BA), shaft-condylar angle (SCA), lateral capitellohumeral angle (LCHA)), as well as data on complications and satisfaction at last follow-up. Fifteen patients were included, with a median follow-up of 81 (64–103) months. All the variables had improved significantly as follows: CA −16 (−18 to −9)°, HUA −16 (−19 to −12)°, BA −11 (−17 to −7)°, SCA 7.5 (3.3 to 13.8)°, LCHA −4.8 (−6.8 to 0.6), flexion 10 (0 to 24)°, and extension 10 (0 to 10)°. The annual correction rate in terms of HUA was 2.41° (1.9 to 3.2). There were 5 cases of aseptic screw loosening, 4 of them requiring replacement, without relation to age at surgery (p = 0.324). Most patients (86.67%) were satisfied, and a relationship was found with younger age at surgery (p = 0.037). In conclusion, preliminary results show that LDHH with the eight-Plate system is an effective technique for mild to moderate cubitus varus deformity correction in children. Patients should be advised of the relatively long duration of implant retention and the possibility of reoperation for screw replacement or implant removal.

Neural wedge osteotomy method of correction for cubitus varus deformity in children

In this study, we evaluated the clinical outcome of neutral wedge osteotomy assisted with the center of rotation of angulation (CORA) method of distal humerus anatomical axis for the treatment of cubitus varus deformity in children. From 2016 to 2019, 20 children with cubitus varus deformity after supracondylar fracture of the humerus were enrolled. Standard anteroposterior radiograph of the humerus was taken preoperatively. The CORA point and angulation angles were obtained by measuring the proximal and distal humerus anatomical axis. During the operation, neutral wedge osteotomy was performed to correct the varus deformity. The Baumann angle and the carrying angle were used to evaluate the correction effect of the distal humeral varus deformity. The average age of the patients was 7.8 years. Patients were followed up for an average of 29.3 months (range, 24-36 months). The average interval between surgery and injury was 12 months. The mean preoperative Baumann angle and carrying angle were 99° (90°-115°) and -14° (range, -10° to -30°), respectively. At the last follow-up, the mean Baumann angle and carrying angle was 76° (70°-80°) and 13.6° (10°-18°), respectively, with 16 cases showing excellent outcome and 4 cases showing good outcome. Our results indicated that the neutral wedge osteotomy assisted with CORA method of distal humerus anatomical axis showed good clinical outcomes in the treatment of cubitus varus deformity in children and is worthy of clinical application. The level of evidence is IV.

COMPARISON OF TWO METHODS OF FIXATION OF SUPRACONDYLAR FRACTURES OF THE HUMERUS IN CHILDREN

Objective:

To compare the outcomes of the fixation of complete and displaced supracondylar humeral fractures in children with two different Kirschner wire configurations.

Methods:

The type of fixation was randomized to either crossed (19 cases), or two divergent lateral Kirschner wires (24 cases). The comparison was made six months later between the two treated groups and each group with the non-fractured elbow (clinical alignment, range of motion, Baumann angle, and lateral humeral capitellar angle).

Results:

43 children were evaluated (65% boys) with a mean age of six years and five months. The carrying angle (p = 0.94), extension (p = 0.89), and the Flynn´s criteria (p = 0.56) were similar between the groups. The flexion was slightly smaller for the crossed wire group (p = 0.04), but similar to the uninjured side. The Baumann angle was not different between the two fixations (p = 0.79) and the contralateral side (p = 0.1). The lateral humeral capitellar angle was slightly greater for the lateral pinning (p = 0.08), but with no difference with the uninjured elbow (p = 0.62). No iatrogenic injuries were observed.

Conclusion:

Both fixations presented similar outcomes that did not significantly affect the carrying angle in relation to the non-fractured side. Level of evidence II, Therapeutic study - Investigating the results of treatment.

Not Kidding! Sequalae of elbow trauma in children

Elbow injuries are common in children and while majority heal very well, some result in deformities of the elbow. Although deformities such as cubitus varus and non-progressive cubitus valgus are considered cosmetic by the paediatric orthopaedic surgeons and intentionally ignored, they are not always benign and can result in functional deficit due to instability, pain, tardy nerve palsies and osteoarthritis later in life. Similarly congenital and developmental conditions that do not cause major functional loss in childhood, become very disabling in adults due to increasing functional demands. Congenital radial head dislocation and radioulnar synostosis fall into this category. In this paper we discuss clinical presentation, treatment options and outcomes of common elbow conditions presenting later in the life.

Accuracy of Conventional Triplane Measures Compared to 3-D Analysis for Assessment of Cubitus Varus Deformities in Adults

Purpose

Cubitus varus is a common triplane deformity in adults associated with supracondylar humeral fractures experienced as a child and consists of varus, extension, and internal rotation components. When corrective osteotomy is indicated, these three components should be measured precisely. This study aimed to evaluate the accuracy of radiographic and physical measurements of cubitus varus deformities in adults compared to values measured on three-dimensional (3-D) bone surface models of the adult bilateral humerus.

Methods

Three-dimensional bilateral humerus models were developed using bilateral humerus CT images of 20 adult patients with cubitus varus. The varus, internal rotation, and extension components of the deformity were assessed by superimposing the 3-D bone model onto a mirror-image model of the contralateral normal humerus. Values obtained from the radiographic and physical measurements were compared with those from the 3D model. The reliability of each measurement was assessed by calculating correlation coefficients (CCs).

Results

Radiographic measurements of the varus and extension components showed good reliability (CC = 0.796 and 0.791, respectively). Physical measurement of the varus component, however, showed only moderate reliability (CC= 0.539), while physical measurement of the extension and internal rotation components exhibited poor reliability (CC = 0.164 and 0.466, respectively).

Conclusion

Varus and extension components of cubitus varus in adults can be reliably measured using conventional methods, whereas the internal rotation component cannot. Thus, 3-D methods with which to quantify the rotational component preoperatively might be needed when the correction of a rotational deformity is considered.

Tardy Ulnar Nerve Palsy

Tardy ulnar nerve palsy is a chronic clinical condition characterized by a delayed onset ulnar neuropathy after an injury to the elbow. Typically, tardy ulnar nerve palsy occurs as a consequence of nonunion of pediatric lateral condyle fractures at the elbow, which eventually lead to a cubitus valgus deformity. While the child grows, the deformity worsens and the ulnar nerve is gradually stretched until classic symptoms of ulnar nerve neuropathy appear. Other childhood elbow trauma has also been associated with tardy ulnar nerve palsy, including supracondylar fractures resulting in cubitus varus, fractures of the medial condyle and of the olecranon, as well as radial head or Monteggia fractures/dislocation, with or without deformity. The clinical assessment includes obtaining a complete history, physical examination, nerve conduction tests, and elbow imaging studies. Treatment consists of ulnar nerve decompression, with or without corrective osteotomy, with overall successful results usually achieved.

Management of supracondylar fractures of the humerus in children

Supracondylar fractures of the humerus are the most frequent fractures of the paediatric elbow, with a peak incidence at the ages of five to eight years.

Extension-type fractures represent 97% to 99% of cases. Posteromedial displacement of the distal fragment is the most frequent; however, the radial and median nerves are equally affected. Flexion-type fractures are more commonly associated with ulnar nerve injuries.

Concomitant upper-limb fractures should always be excluded. To manage the vascular status, distal pulse and hand perfusion should be monitored. Compartment syndrome should always be borne in mind, especially when skin puckering, severe ecchymosis/swelling, vascular alterations or concomitant forearm fractures are present.

Gartland’s classification shows high intra- and inter-observer reliability. Type I is treated with casting. Surgical treatment is the standard for almost all displaced fractures. Type IV fractures can only be diagnosed intra-operatively.

Closed reduction and percutaneous pinning is the gold standard surgical treatment. Open reduction via the anterior approach is indicated for open fractures, absence of the distal vascular flow for > 10 to 15 minutes after closed reduction, and failed closed reduction.

Lateral entry pins provide stable fixation, avoiding the risk of iatrogenic ulnar nerve injury.

About 10% to 20% of displaced supracondylar fractures present with alterations in vascular status. In most cases, fracture reduction restores perfusion.

Neural injuries occur in 6.5% to 19% of cases involving displaced fractures. Most of them are neurapraxias and it is not routinely indicated to explore the nerve surgically.

Cite this article: EFORT Open Rev 2018;3:526-540. DOI: 10.1302/2058-5241.3.170049

Elbow Posterolateral Rotatory Instability due to Cubitus Varus and Overuse

A malunion as a complication of distal humerus fractures has been frequently linked with aesthetic problems but less frequently with posterolateral rotatory instability. We report 2 cases of childhood posttraumatic cubitus varus with subsequent posterolateral rotatory instability and their treatment with a minimum of 2 years of follow-up. The etiology of the so-called posterolateral rotatory instability of the elbow is mostly traumatic, but iatrogenic causes have also been described such as the treatment of tennis elbow and less frequently and chronically due to overuse and overload because of distal humerus malunion.

Altered bone density and stress distribution patterns in long-standing cubitus varus deformity and their effect during early osteoarthritis of the elbow

OBJECTIVE

To quantify the bone density and stress distribution patterns in long-standing cubitus varus and clarify the effects of the deformity on bone density.

DESIGN

We created three-dimensional computed tomography (CT) elbow models from 21 patients with long-standing cubitus varus deformities without advanced osteoarthritis (OA) and assessed the deformity by superimposing the affected humerus onto a mirror-image of the contralateral normal. Elbows were divided into 13 regions before measuring the bone density of each region and comparing the percentage of high-density volume (%HDV) between affected and normal sides. We constructed finite element models and quantitatively analyzed stress distribution.

RESULTS

Average degrees of deformities were 20.1° of varus, 6.4° of extension, and 12.7° of internal rotation. The medial side of the affected humerus and ulna, Anteromedial trochlea (P < 0.001), Medial coronoid (P = 0.004), and Medial olecranon (P = 0.049) had significantly higher %HDVs than their normal counterparts. Conversely, %HDVs on the affected lateral side, Capitellum (P < 0.001), Anterolateral trochlea (P = 0.010), Posterolateral trochlea (P < 0.001), Lateral coronoid (P = 0.007), and Lateral olecranon (P < 0.001) were significantly lower than the normal side. The affected radial head %HDVs at Anterolateral and Posteromedial quadrants were high (P = 0.007) and low (P = 0.007), respectively. The bone density distribution coincided with stress distribution patterns revealed by finite element analysis (FEA), except in the lateral region influenced by forearm rotation.

CONCLUSIONS

Repetitive stress on the medial elbow may alter bone density distribution patterns, probably presenting from early stage of OA.

Myoclonic movements of the elbow and wrist as a rare complication of supracondylar humerus fracture in a child

Supracondylar humerus fractures are associated with neurological complications. This report describes a child who suffered from persistent myoclonus-like movements of the elbow and wrist as a consequence of a previous displaced fracture. Symptoms were progressive. Seven years later, sensation was decreased in the ulnar nerve distribution. Palpation of the ulnar nerve exacerbated the myoclonic jerks. As symptoms progressed, electoneuromyography became abnormal. Cubital tunnel release and anterior transposition of the ulnar nerve were required to reach full recovery. Long-term outcome was excellent. In conclusion, myoclonus-like movements are a rare complication of supracondylar humerus fractures, resulting from ulnar nerve injury.

Cubitus Varus-It's More Than Just a Crooked Arm!

Although cubitus varus has been regarded as a purely cosmetic problem in the pediatric population, symptomatic elbow instability, and ulnar neuropathy from the mechanical axis malalignment have been reported in adults. This overview discusses the biomechanical axis disruption that leads to soft tissue and morphologic bony alterations in the elbow and offers a compelling argument for corrective osteotomy to treat pediatric cubitus varus.

A Simple Dual-Planar Osteotomy to Correct Cubitus Varus Deformity in Children

OBJECTIVES

To report the outcomes when performing a dual-planar osteotomy of the distal humerus via a posterior approach for gunstock deformity in children.

DESIGN

A retrospective review.

SETTING

Penn State Hershey Pediatric Bone and Joint Institute.

PATIENTS/PARTICIPANTS

Sixteen patients were reviewed. The average patient age was 8 years (range, 5-13 years).

INTERVENTION

A complete dual-planar closing wedge osteotomy was performed with the patient in the prone position via a posterior triceps-splitting approach. Fixation with buried smooth K wires was utilized.

MAIN OUTCOME MEASUREMENTS

Valgus correction obtained, final elbow range of motion, radiographic and clinical correction of the deformity, the patient's satisfaction, and elbow function were evaluated.

RESULTS

Preoperative radiographs showed the average humeral-ulnar angle (HUA) was 17 degrees of varus (range, 10-26 degrees varus). The average wedge removed wallow-up clinical exam demonstrated that the carrying angle was in valgus in 15 cases and neutral in 1 case. The average carrying angle was 5 degrees of valgus (range, 0-11 degrees valgus). The average hyperextenss 25 degrees (range, 20-40 degrees). Duration of follow-up averaged 51 months (range, 12-126 months). Final foion deformity improved from 9 degrees preoperatively to 1 degree postoperatively. Outcomes were classified by the grading scale described by Oppenheim: 14 cases had excellent results and 2 cases had good results.

CONCLUSIONS

This method provides clear visualization and excellent correction of the deformities. The posterior scar is cosmetically acceptable. We recommend this technique for the treatment of gunstock deformity in children.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Nerve injuries associated with supracondylar fractures of the humerus in children

Aims

We aimed to identify the pattern of nerve injury associated with paediatric supracondylar fractures of the humerus.

Patients and Methods

Over a 17 year period, between 1996 and 2012, 166 children were referred to our specialist peripheral nerve injury unit. From examination of the medical records and radiographs were recorded the nature of the fracture, associated vascular and neurological injury, treatment provided and clinical course.

Results

Of the 166 patients (111 male, 55 female; mean age at time of injury was seven years (standard deviation 2.2)), 26 (15.7%) had neurological dysfunction in two or more nerves. The injury pattern in the 196 affected nerves showed that the most commonly affected nerve was the ulnar nerve (43.4%), followed by the median (36.7%) and radial (19.9%) nerves. A non-degenerative injury was seen in 27.5%, whilst 67.9% were degenerative in nature. Surgical exploration of the nerves was undertaken in 94 (56.6%) children. The mean follow-up time was 12.8 months and 156 (94%) patients had an excellent or good clinical outcome according to the grading of Birch, Bonney and Parry.

Conclusion

Following paediatric supracondylar fractures we recommend prompt referral to a specialist unit in the presence of complete nerve palsy, a positive Tinel’s sign, neuropathic pain or vascular compromise, for consideration of nerve exploration. Take home message: When managed appropriately, nerve recovery and clinical outcomes for this paediatric population are extremely favourable. Cite this article: Bone Joint J 2016;98-B:851–6.

French Osteotomy for Cubitus Varus in Children: A Long-term Study Over 27 Years

BACKGROUND

Cubitus varus is a cosmetically unacceptable complication of supracondylar fractures of the elbow in children. We have performed the lateral closing wedge (French) osteotomy to correct the varus for 27 years. More complex osteotomies have been described to correct the associated hyperextension and internal rotation deformities and to prevent a prominent lateral condyle.

METHODS

We retrospectively reviewed 90 consecutive patients (1986 to 2012). The mean age of the patients at surgery was 8.2 years (3 to 14 y). The varus angle (mean, 21.4 degrees; range, 8 to 40 degrees) was assessed preoperatively with the humero-elbow-wrist angle. The postoperative carrying angle (mean, 10.4 degrees) and the preoperative and postoperative range of movement were assessed clinically. The lateral condylar prominence index (LCPI) was retrospectively measured at union.

RESULTS

Eighty-four (93.3%) of the patients had a good or excellent result. Six (6.7%) had a poor result (residual varus, loss of >20 degrees of preoperative range of flexion or extension or a complication necessitating resurgery). There were no neurovascular complications. The mean LCPI was +0.14.

CONCLUSIONS

The results of the French osteotomy are comparable with the more technically demanding dome, step-cut translation, and multiplanar osteotomies, with a lower complication rate. The literature reports adequate remodeling of the hyperextension deformity (≤10 y) and the LCPI (≤12 y), and that the internal rotation deformity is well tolerated by the patient.

LEVEL OF EVIDENCE

Level IV-case series.

Tardy ulnar nerve palsy after fracture non-union medial epicondyle of humerus - An unusual case

Tardy ulnar nerve palsy is a chronic clinical condition characterised by delayed onset ulnar neuropathy. Typically tardy ulnar nerve palsy occurs as a consequence of non-union of lateral condyle in child resulting in cubitus valgus deformity which ultimately is the cause of ulnar nerve palsy. However very few literature are available for tardy ulnar nerve palsy as a result of old fracture of medial epicondyle without cubitus varus or valgus deformity. We report a rare case of tardy ulnar nerve in an adult male with fracture non-union of medial epicondyle of humerus.

Ulnar nerve morbidity as a long-term complication of pediatric supracondylar humeral fracture

BACKGROUND

Supracondylar humeral fractures are common in children. We studied long-term ulnar nerve symptoms secondary to these fractures and analyzed the treatment for ulnar neuropathy.

MATERIALS AND METHODS

The cohort included 91 patients with a supracondylar humeral fracture in childhood, on average 12 years previously, in the geographic catchment area. All the cases were reexamined in regard to ulnar nerve morbidity. Cases with secondary ulnar neuropathy were treated nonoperatively and operatively.

RESULTS

Ulnar neuropathy was present in four cases (4.4 %). They all had suffered from a dislocated fracture, and they had been operated primarily. Another three patients had slight ulnar nerve symptoms. Hence, the total prevalence of secondary ulnar nerve morbidity was 7.7 %. A jumping nerve was seen in 9.9 %; 51.6 % had a diminished axial angle.

CONCLUSIONS

We report a defined pattern of long-term ulnar nerve morbidity after pediatric supracondylar humeral fracture. The prevalence of neuropathy is alarming in the young population (<25 years of age).

Does cubitus varus cause morphologic and alignment changes in the elbow joint?

BACKGROUND

In cubitus varus after pediatric supracondylar fracture, late development of trochlear deformity causing additional varus angulation and joint misalignment relating to late complications of the tardy ulnar nerve palsy or posterolateral rotatory instability have been suggested. However, it is unclear whether these morphologic and alignment changes of the elbow joint occur in cubitus varus. The object of this study was to investigate morphologic changes of the bones and alignment changes of the elbow joint in longstanding cubitus varus using 3-dimensional computer bone models created from computed tomography data.

MATERIALS AND METHODS

We studied 14 patients with longstanding cubitus varus after pediatric supracondylar fractures. Three-dimensional bone models of the bilateral humerus, radius, and ulna were created from computed tomography data. We compared the morphology and alignment of the elbow joint between the affected side and contralateral unaffected side.

RESULTS

The posterior trochlea, distal part of the lateral capitellum, diameters of the radial head, and articular surface of the ulna in cubitus varus were larger than those of the contralateral elbow. In the ulna, the convex portion of the trochlear notch shifted laterally in cubitus varus. Joint alignment in cubitus varus was affected by a shift of the ulna to a more distal and medial position with external rotation and flexion.

CONCLUSIONS

In longstanding cubitus varus, the morphology and alignment of the elbow joint are observed to differ from those of the normal side.

Ultrasonographic findings in cubital tunnel syndrome caused by a cubitus varus deformity

We have retrospectively reviewed the clinical, preoperative ultrasonographic, and operative findings of eight patients who had tardy ulnar nerve palsy caused by a cubitus varus deformity. The mean varus angle on the affected side was 23°. With preoperative ultrasonography, the anterior dislocation of the ulnar nerve from the medial epicondyle was detected in dynamic scanning of short-axis images, and long-axis images revealed nerve compression and kinking in the proximal border of the flexor carpi ulnaris. Operative findings revealed compression of the ulnar nerve by a fibrous band, which was released in all cases. The cause of the tardy ulnar nerve palsy in this series of patients was constriction by a fibrous band and kinking in the proximal border of the flexor carpi ulnaris due to ulnar nerve dislocation from compression resulting from the forward movement of the medial head of the triceps brachii muscle.

Corrective dome osteotomy for cubitus varus and valgus in adults

A corrective dome osteotomy was performed in 19 adult patients for cubitus varus and valgus deformity. The mean age at operation was 31.1 years and the mean follow-up was 41 months. The average postoperative carrying angle in 16 patients with cubitus varus was 6.1 degrees (range, 1-10 degrees), an average correction of 24 degrees (range, 5-36 degrees). The average postoperative carrying angle in 3 patients with cubitus valgus was 6.7 degrees (range, 6-7 degrees), an average correction of 29.3 degrees (range, 29-30 degrees). None of the patients had recurrence of deformity, unsightly scarring, or a prominent lateral or medial condyle at final follow-up. An excellent result was achieved in 13 patients and good in 6. We conclude that corrective dome osteotomy with secure fixation using plates and screws is a reliable option for cubitus varus or valgus deformity in adults.

Tardy ulnar nerve palsy in cubitus varus deformity associated with ulnar nerve dislocation in adults

Seven patients with tardy ulnar nerve palsy from a posttraumatic cubitus varus deformity were reviewed retrospectively. The severity of symptoms was grade I in 3 patients and grade II in 4 patients according to McGowan's classification. The mean internal rotation angle was 30.7 degrees (range, 25 degrees -45 degrees ). The most prominent feature was dislocation of the nerve anterior to the medial epicondyle and entrapment of the nerve by the fibrous band of the flexor carpi ulnaris muscle. Of these 7 patients, 4 were treated by 3-dimensional osteotomy with ulnar nerve transposition, and 3 were treated by anterior transposition of the ulnar nerve. All patients improved clinically, and there was no significant difference between anterior transposition of the nerve in the group with osteotomy and the group without osteotomy. Ulnar nerve instability due to internal rotation deformity and distal entrapment was considered to be the main cause of neuropathy.

Medial or lateral dislocation (snapping) of a portion of the distal triceps: a biomechanical, anatomic explanation

Medial and lateral snapping (dislocation) of the distal triceps over the epicondyle during elbow flexion has been reported but is frequently misdiagnosed and is not well understood. In this study a mathematical model was designed to simulate the effect that bony abnormalities at the distal humerus and soft tissue variations of the distal triceps have on the line of pull of the triceps. The predictions were then tested on prefabricated and fabricated plastic elbow models, as well as 8 cadaveric elbows. When the bony alignment was altered, varus angulation had the greatest effect: 30 degrees varus malalignment of the distal humerus displaced the centroid of the triceps vector medially by approximately 2.0 cm. Valgus malalignment had a lesser effect: 30 degrees valgus displaced it laterally by 1.5 cm. Negligible effects on the triceps line of pull were seen with internal or external malrotation and with flexion or extension malalignment. Of the soft tissue alterations, displacement of the triceps insertion had a greater effect than movement of the triceps origin. The triceps vector was displaced by approximately 70% of the amount of translation of the triceps insertion. The relationship between the triceps line of pull and the bony alignment is represented by the triceps (T) angle. Our use of the T angle to understand snapping triceps is analogous to the use of the quadriceps (Q) angle for patellar subluxation/dislocation. Treatment should aim to restore normal triceps biomechanics with soft tissue or bony procedures.

Tardy posterolateral rotatory instability of the elbow due to cubitus varus

BACKGROUND

Cubitus varus has long been considered merely a cosmetic deformity. The purpose of this paper is to demonstrate a causal relationship between cubitus varus and instability of the elbow.

METHODS

In twenty-four patients (twenty-five limbs) with a cubitus varus deformity following a pediatric distal humeral fracture or resulting from a congenital anomaly (three limbs of two patients), tardy posterolateral rotatory instability of the elbow developed approximately two to three decades after the deformity occurred. All patients presented with lateral elbow pain and recurrent instability. The average varus deformity was 15 degrees (range, 0 degrees to 35 degrees ). Surgery was performed in twenty-one patients (twenty-two limbs). Treatment consisted of reconstruction of the lateral collateral ligament and osteotomy in seven limbs, ligament reconstruction alone in ten, osteotomy alone in four, and total elbow arthroplasty in one.

RESULTS

In three patients, the triceps muscle was dynamically stimulated intraoperatively to contract while resisting extension of the elbow. This produced posterolateral rotatory subluxation of the elbow, which was reversed by corrective osteotomy and lateral transposition of a portion of the medial head of the triceps that originally had been attached to the elongated, deformed medial aspect of the olecranon. At an average of three years (minimum, one year) after the operation, the result was good or excellent for nineteen of the twenty-two limbs that had undergone an operation; three limbs had persistent instability.

CONCLUSIONS

With cubitus varus, the mechanical axis, the olecranon, and the triceps line of pull are all displaced medially. The repetitive external rotation torque on the ulna permitted by these deformities can stretch the lateral collateral ligament complex and lead to posterolateral rotatory instability. Thus, cubitus varus deformity secondary to supracondylar malunion or congenital deformity of the distal part of the humerus may not always be a benign condition and may have important long-term clinical implications. Operative correction can relieve symptoms of instability. The indications for preventive corrective osteotomy remain to be determined.

Cubitus varus associated with dislocation of both the medial portion of the triceps and the ulnar nerve

Five patients with cubitus varus deformities from malunited childhood fractures had dislocation (snapping) of both the medial portion of the triceps and the ulnar nerve over the medial epicondyle. In addition to snapping, these patients had medial elbow pain or ulnar nerve symptoms. Cubitus varus shifts the line of pull of the triceps more medial, which can cause anteromedial displacement of the medial portion of the triceps during elbow flexion. The ulnar nerve is concomitantly pushed or pulled anteromedially by the triceps, and ulnar neuropathy may result from friction neuritis or from dynamic compression by the triceps against the epicondyle. Recognition of both the dislocating ulnar nerve and the snapping medial triceps is crucial in the successful treatment of this pathologic finding. In symptomatic individuals, we recommend either corrective valgus osteotomy of the distal humerus or partial excision or lateral transposition of the snapping medial triceps, or a combination of both. Alternatively, medial epicondylectomy can also eliminate the snapping. Transposition of the ulnar nerve can be performed for ulnar nerve symptoms and/or ulnar nerve instability. Using this approach, correction of the snapping and/or ulnar nerve symptoms was achieved in all cases.