Radial head replacement with the 3D-printed patient-specific titanium prosthesis: Preliminary results of a multi-centric prospective study

PURPOSE

To report preliminary clinical results and safety of 3D-printed patient-specific titanium radial head (RH) prosthesis in treatment of the irreparable RH fractures.

MATERIAL AND METHODS

This multi-centric prospective study included 10 patients (6 men and four women, mean age 41 years (range, 25-64 years)). Three cases were classified as Mason type III and 7 cases as type IV. Patients were assessed preoperatively, intraoperatively, and at 1, 6, 12, 24, 36, and 48 weeks postoperatively. Range of motion (ROM), visual analog scale (VAS) score, Disabilities of the Arm, Shoulder and Hand (DASH) score, Mayo Elbow Performance Score (MEPS), radiology imaging, and laboratory blood and urine testing were evaluated.

RESULTS

The prostheses were implanted utilizing cemented stems in 5 patients and cementless stems in 5 patients. Intraoperatively, well congruency of a prosthesis with capitellum and radial notch of ulna was observed in all cases. All patients had improvement of ROM, VAS score, DASH score, and MEPS during the postoperative follow-ups. At the final follow-up, mean elbow extension was 6.5° (range, 0°-30°), flexion 145° (range, 125°-150°), supination 79° (range, 70°-80°), and pronation 73.5° (range, 45°-80°). Mean VAS score was 0.3 (range, 0-3), DASH score was 12.35 (range, 1.7-23.3), and MEPS was 99.5 (range, 95-100). Postoperative radiographs demonstrated heterotopic ossification in 2 cases, periprosthetic radiolucency in 2 cases, and proximal radial neck resorption in 2 cases. No one had the evidence of capitellar erosion, implant failure, malpositioning, overstuffing, or symptomatic stem loosening. There was no significant alteration of laboratory results or adverse events related to the 3D-printed prosthesis implantation.

CONCLUSION

The preliminary results demonstrated that implantation of the 3D-printed patient-specific titanium RH prosthesis is safe and may be a potential treatment option for irreparable RH fracture.

Double right triangular shape full-thickness skin grafts technique for short rectangular or square shape donor site defect - original method with a case report

Full-thickness skin grafts are essential tools for reconstructive surgery. Rectangular or square secondary defect usually occurs after performing a cross-finger flap or homodigital island flap. With the traditional fusiform ellipse design, trimming out excess graft tissue is necessary. Double right triangular shape full-thickness skin grafts are designed to correct the problem.

Surgical Treatment for Trigger Thumb Using a Radial Approach

The anatomy of the thumb flexor pulley system and surrounding structures differs from the fingers. The hand's positioning during trigger thumb release is troublesome. Iatrogenic radial digital nerve injuries of the thumb following opened or percutaneous A1 pulley release have been reported. We present the radial approach using a transverse incision for surgical release of the trigger thumb. This surgical approach aimed to restore a familiar surgical hand position, prevent radial digital nerve injury and bowstringing of the flexor pollicis longus, and decrease postoperative pain to facilitate recovery of hand function.

What Are the MSTS Scores and Complications Associated With the Use of Three-dimensional Printed, Custom-made Prostheses in Patients Who Had Resection of Tumors of the Hand and Foot?

BACKGROUND

There are a few good options for restoring bone defects in the hand and foot. 3D-printed implants have been used in the pelvis and elsewhere, but to our knowledge, they have not been evaluated in the hand and foot. The functional outcome, complications, and longevity of 3D-printed prostheses in small bones are not well known.

QUESTIONS/PURPOSES

(1) What are the functional outcomes of patients with hand or foot tumors who were treated with tumor resection and reconstruction with a 3D-printed custom prosthesis? (2) What complications are associated with using these prostheses? (3) What is the 5-year Kaplan-Meier cumulative incidence of implant breakage and reoperation?

METHODS

Between January 2017 and October 2020, we treated 276 patients who had tumors of the hands or feet. Of those, we considered as potentially eligible patients who might have extensive loss in their joint that could not be fixed with a bone graft, cement, or any prostheses available on the market. Based on this, 93 patients were eligible; a further 77 were excluded because they received nonoperative treatment such as chemoradiation, resection without reconstruction, reconstruction using other materials, or ray amputation; another three were lost before the minimum study follow-up of 2 years and two had incomplete datasets, leaving 11 for analysis in this retrospective study. There were seven women and four men. The median age was 29 years (range 11 to 71 years). There were five hand tumors and six tumors of the feet. Tumor types were giant cell tumor of bone (five), chondroblastoma (two), osteosarcoma (two), neuroendocrine tumor (one), and squamous cell carcinoma (one). Margin status after resection was ≥ 1 mm. All patients were followed for a minimum of 24 months. The median follow-up time was 47 months (range 25 to 67 months). Clinical data; function according to the Musculoskeletal Tumor Society, DASH, and American Orthopedic Foot and Ankle Society scores; complications; and survivorship of implants were recorded during follow-up in the clinic, or patients with complete charts and recorded data were interviewed on the telephone by our research associates, orthopaedic oncology fellows, or the surgeons who performed the surgery. The cumulative incidence of implant breakage and reoperation was assessed using a Kaplan-Meier analysis.

RESULTS

The median Musculoskeletal Tumor Society score was 28 of 30 (range 21 to 30). Seven of 11 patients experienced postoperative complications, primarily including hyperextension deformity and joint stiffness (three patients), joint subluxation (two), aseptic loosening (one), broken stem (one), and broken plate (one), but no infection or local recurrence occurred. Subluxations of the metacarpophalangeal and proximal interphalangeal joints in two patients' hands were caused by the design of the prosthesis without a joint or stem. These prostheses were revised to a second-generation prosthesis with joint and stem, leading to improved dexterity. The cumulative incidence of implant breakage and reoperation in the Kaplan-Meier analysis was 35% (95% CI 6% to 69%) and 29% (95% CI 3% to 66%) at 5 years, respectively.

CONCLUSION

These preliminary findings suggest that 3D implants may be an option for reconstruction after resections that leave large bone and joint defects in the hand and foot. Although the functional results generally appeared to be good to excellent, complications and reoperations were frequent; thus, we believe this approach could be considered when patients have few or no alternatives other than amputation. Future studies will need to compare this approach to bone grafting or bone cementation.

LEVEL OF EVIDENCE

Level IV, therapeutic study.

Triple suture fixation for displaced comminuted olecranon fracture with a stable ulnohumeral joint

PURPOSE

To report the outcome of a novel fixation technique using three high-strength sutures which is including articular buttress suture, cerclage suture, and tension band with off-loading triceps suture (triple suture fixation) in the treatment of displaced comminuted olecranon fracture with a stable ulnohumeral joint (Mayo type IIB). The rationale of using this technique is that the sutures have been used to stabilize multiple fracture fragments in all sides of the olecranon.

MATERIAL AND METHODS

Between July 2018 and July 2021, 10 patients (7 women, 3 men; mean age, 49.9 years; mean follow-up duration, 27.8 months) with Mayo type IIB olecranon fractures who underwent triple suture fixation were included in the study. The elbow was immobilized in a splint for 2 weeks postoperatively. Range-of-motion exercises were initiated after splint removal and weight bearing was allowed at 6 weeks postoperatively.

RESULTS

Average active range of motion of the elbow was 145° of flexion (range, 135°-150°), 6.5° of extension (range, 0°-30°), 83° of supination (range, 70°-85°), and 77.5° of pronation (range, 70°-80°). Mean MEPS was 98.3 (range, 85-100) and DASH score was 3.1 (range, 0-10) at the final follow-up. Radiographic data at the final follow-up analyzed by paired t test demonstrated that there was no statistically significant difference of proximal olecranon height (OH), trochlear notch width (TW), and OH/TW ratio between postoperative treatment and normal side (p-value >.05). No complication of implant prominence, fixation failure, nonunion, infection or heterotopic ossification was found postoperatively. Breakage of drill bit occurred during drilling a distal oblique hole for articular buttress suture in one patient.

CONCLUSION

The triple suture fixation is an effective treatment with low incidence of complications in treatment of Mayo type IIB olecranon fractures. Larger comparative studies are needed to confirm the value of such technique.

The patient-specific implant created with 3D printing technology in treatment of a severe open distal humerus fracture with complete loss of the lateral column

The open distal humeral fracture associated with the major loss of the articular surface and bony structure is a challenging problem for orthopedic surgeons. In this case report, we describe a case of complete missing lateral column of the distal humerus with severe articular destruction of capitellum and lateral trochlear ridge which was treated with the patient-specific implant created with three-dimensional printing technology. Apart from anatomic replacement of the articular surface, the lateral collateral ligament complex and extensor muscle which are the key soft tissue stabilizers of elbow were repaired by reattaching their bony origins to the impacted iliac crest bone graft inside the implant. Due to the favorable result at 2-year follow-up, this modality is a potentially viable surgical option in treating of the severe open distal humeral fracture associated with entire lateral condylar damage.

A custom-made distal humerus plate fabricated by selective laser melting

This study aims to evaluate the mechanical performance of custom 3D-printed titanium plates in the treatment of distal humerus fractures. Rigidity of four plating configurations were investigated by finite element analysis. The results reveal that implementation of custom designs with minimal screw holes, lateral-medial linking screw and lateral brim could significantly improve stiffness and consequently leads to better biomechanical stability as compared to standard osteosynthesis design. Biomechanical testing was also performed to validate practical usability. The results confirm that newly designed custom plates fabricated by selective laser melting is a possible alternative for the treatment of distal humerus fracture.

Precision of computed tomography and cartilage-reproducing image reconstruction method in generating digital model for potential use in 3D printing of patient-specific radial head prosthesis: a human cadaver study

Background

A prosthetic replacement is a standard treatment for an irreparable radial head fracture; however, the surface mismatch of the commercially available designs is concerned for the long-term cartilage wear. The patient-specific implant created from 3D printing technology could be favorable in replicating the normal anatomy and possibly reduce such sequela. Our study aimed to assess the precision of the computed tomography (CT) and cartilage-reproducing image reconstruction method (CIRM) in generating digital models for potentially use in manufacturing the patient-specific prosthesis from 3D printing.

Methods

Eight intact  elbows (3 right and 5 left) from 7 formalin-embalmed cadavers (4 males and 3 females) with mean age of 83 years (range, 79–94 years) were used for this study. Computerized 3D models were generated from CT, and CIRM. The cartilage-reproducing image reconstruction method has compensated the cartilage profile based on the distance between the subchondral surfaces of the radial head and surrounding bones in CT images. The models of actual radial head geometry used as the gold standard was generated from CT arthrography (CTA). All models of each specimen were matched by registering the surface area of radial neck along with the tuberosity. The difference of head diameter, head thickness, and articular disc depth among three models was evaluated and analyzed by Friedman ANOVA and multiple comparison test using Bonferroni method for statistical correction. A p-value of less than 0.01 was considered statistically  significant. The difference of overall 3D geometry was measured with the root mean square of adjacent point pairs.

Results

The analysis displayed the difference of diameter, thickness, and disc depth across the models (p< 0.01). Pairwise comparisons revealed statistically significant difference of all parameters between CTA models and CT models (p< 0.01) whereas no difference was found between CTA models and CIRM models. The mean difference of overall 3D geometry between CTA models and CT models was 0.51±0.24 mm, and between CTA models and CIRM models was 0.24±0.10 mm.

Conclusions

CIRM demonstrated encouraging results in reestablish the normal anatomy and could be potentially used in production process of 3D printed patient-specific radial head prosthesis.

A biomechanical comparison of different tying techniques of a double-stranded looped suture

PURPOSE

This study aims to assess the biomechanical performance of different tying techniques of a double-stranded looped suture (DSLS).

METHODS

Loop and knot security of DSLS tying techniques (nice knot (NK), modified nice knot (MNK), double-twist knot (DTK), and double-barrel knot (DBK)) were compared. The square knot of DSLS (SKD) and the square knot of single-stranded suture (SKS) had been used as references. Twenty-four loops of each configuration were created using No. 2 Fiberwire (Arthrex, Naples, Florida, USA) and tested with a material testing machine. Samples were loaded with 10 N preloads for loop security assessment. Knot security was subsequently evaluated. Twelve loops of each knot were loaded to failure. The rest were subjected to cyclic load testing and the elongation at the 50th and 1000th cycles were measured. Knot bulkiness was determined by measuring knot height before testing. Data were compared with analysis of variance and post hoc tests. Statistical significance was p < 0.05.

RESULTS

All knots showed no statistically significant difference in displacement with preload. The load-to-failure was highest in NK, followed by MNK, DTK, DBK, SKD, and SKS. The cyclic loading test at the 50th cycle and the 1000th cycle demonstrated that NK has significantly less displacement than the others except MNK. DTK provided a minimal average knot height followed by NK, SKS, DBK, MNK, and SKD.

CONCLUSION

The different tying techniques in DSLS provided the similar loop security but different knot security and knot bulkiness. NK and MNK are biomechanically superior to the other knots, whereas DTK is the least bulky. The findings in the present study may help set the guide for the surgeons to select the tying technique of DSLS to best suit their requirement.

Matching precision of the reverse contralateral radial head in generating of the individualized prosthesis from the surface registration in tuberosity-neck and in tuberosity-diaphysis

PURPOSE

Following the radial head replacement, the surface mismatches between the implants and the morphological characteristics of the original proximal radius decreased contact areas and increased contact forces which is potential for the long-term articulating cartilage wear. Several studies demonstrated that the individualized prosthesis, created from computed tomographic (CT) images of the contralateral side with the reverse engineering technology, may reduce the mismatch. The aim of this study is to demonstrate the matching precision of the reverse contralateral head between the surface registration in tuberosity-neck (TN) area and in tuberosity-diaphysis (TD) area.

MATERIALS AND METHODS

High-resolution CT scan of 11 pairs of the cadaveric arms was performed. Utilizing advanced image processing techniques, three-dimensional (3-D) models of each specimen was generated. The model of the left side was reversed and matched with the model of the right side in the same cadaver by registering in the area of radial neck along with tuberosity (TN) and in the area of radial tuberosity combined with 2 cm of proximal diaphysis (TD). The alteration of the head diameter, dish diameter, articular depth, head thickness, end-plane angle, offset, and head volume were evaluated and analyzed by paired t-test.

RESULTS

No statistically significant difference was found in all parameters from both TN and TD registrations ( p < 0.05).

CONCLUSION

The surface registration in either TN or TD area can generate the statistically symmetrical 3-D model with the original head. The registration in these areas may possibly be used in creating the individualized radial head prosthesis.

Midterm outcome of partial radial head replacement with a contoured iliac crest bone graft in complex elbow dislocation

PURPOSE

To report the midterm outcome of a novel reconstructive technique using a contoured iliac crest bone graft for partial radial head replacement in the treatment of complex elbow dislocation.

MATERIAL AND METHODS

Between January 2008 and December 2013, 10 patients (5 women, 5 men; mean age, 43.8 years; mean follow-up duration, 65.9 months) with complex elbow dislocation who underwent the partial radial head replacement with the contoured bone graft were included in the study. The irreparable radial head defects averaged 49% of the articular surface (range, 36-60%). The fracture involved the entire head in four patients and partial head in six patients.

RESULTS

At the final follow-up, the mean elbow extension was 8°, flexion 143°, supination 76.5°, and pronation 73°. The mean Mayo elbow performance index was 93.2 points and the Broberg-Morrey functional rating score was 94.1 points, with seven excellent cases, two good cases, and one fair case. Radiographic union was achieved in all but one, at an average time of 6.89 weeks (range, 6-10 weeks). The final radiographs demonstrated no evidence of degenerative change in eight patients, mild arthritis in one patient, and moderate arthritis in one patient.

CONCLUSION

This technique is a viable option in the treatment of the large radial head defect in complex elbow dislocation when more than 40% of the original head is still available for incorporation.

Different Dosages of Triamcinolone Acetonide Injection for the Treatment of Trigger Finger and Thumb: A Randomized Controlled Trial

BACKGROUND

This study was designed to compare the efficacy and complications between 3 different dosages of triamcinolone acetonide for the treatment of trigger finger.

METHODS

Ninety-three patients with a total of 120 trigger digits were included in the study. The involved digits were randomized to 3 groups. Each group received treatment consisting of injection with 5, 10 or 20 mg triamcinolone acetonide. The clinical response to the steroid was evaluated during the first six weeks after injection. The success rate was determined at 3, 6, 9 and 12 months after injection.

RESULTS

After the injections, pain and triggering improved gradually and nearly resolved completely at 6 weeks in all dosages. A dose related pattern was found at 3 and 6 months after the injection. The 20 mg group had a significant higher success rate when compared to the 5 and 10 mg at 3 and 6 months. The 10 mg group has significant higher success rate when compare to 5 mg at 3 months. There were no differences of success rate between groups at 9 and 12 months. At 12 months, 7 of 40 digits (17.5%) in the 5 mg group, 7 of 40 digits (17.5%) in the 10 mg group, and 9 of 40 digit (22.5%) in the 20 mg group were without triggering (p = 0.806).

CONCLUSIONS

A dose-response characteristic was demonstrated in the treatment of trigger finger with triamcinolone acetonide. Triamcinolone acetonide 5 mg seems to have the lowest success rate.

Tarsal tunnel syndrome associated with a perforating branch from posterior tibial artery: a case report

Tarsal tunnel syndrome, a compressive neuropathy of the tibial nerve or its branches with in the tarsal tunnel, is an uncommon condition. Various etiologies of the syndrome have been described. We report a rare case of tarsal tunnel syndrome associated with a perforating branch from the posterior tibial artery. A 56-year-old woman presented with 1-year history of paresthesia and hypoesthesia in the medial and lateral plantar area of the left foot. Tinel's sign was elicited at the tarsal tunnel. Electrodiagnostic studies confirmed the diagnosis of left tarsal tunnel syndrome. Intraoperatively, the perforating branch from posterior tibial artery which traveled through a split in the tibial nerve was encountered. The patient's symptom improved significantly at 2 years after tarsal tunnel release and vascular ligation. Only a minor degree of paresthesia remains in the forefoot.

Neural Anatomy of the Anterolateral Thigh Flap

The anterolateral thigh (ALT) flap is one of the commonly used sensate flaps for intra-oral, hand, and foot reconstruction. The objective of this study was to describe the anatomic location of the sensory nerves supplying the ALT flap in relation to the surface landmarks and with the vascular pedicles. The dissections were carried out in 28 embalmed specimens. An axial line from the anterior superior iliac spine to the superolateral border of the patella and two circles with radii of 5 and 10 cm centered on the midpoint of the former line were used for the surface landmarks. At the intersection point of the axial line and the 10-cm circle, the main lateral femoral cutaneous nerve (LFCN) and its anterior branch were located within 1 and 2.4 cm, respectively. At the intersection point of the axial line and the 5-cm circle, the anterior branch of the LFCN was located within 2.8 cm. The anterior branch of the LFCN can be detected within 3 cm from the central perforator pedicle in all specimens. The posterior branch of the LFCN, superior perforator nerve, and median perforator nerve were found in more variable locations. The findings from our study provide additional information for clinical use in the planning of sensate ALT flap harvest.

Comparative study of the pullout strength of the 2.4-mm AO locking screw, 2.0-mm AO cortical screw and Herbert screw in sawbones: a biomechanical study

BACKGROUND

Headless screw is a standard implant for an osteochondral fragment fixation. With a threaded design, the screw head can be buried under the articular cartilage to prevent a post-traumatic arthritis. However, the screw is expensive and maybe not available in the emergency situation. The 2.4-mm AO locking screw also has a threaded head which is able to advance underneath the cartilage. This has been usedfor fixation of the osteochondal fracture clinically. We compared the pullout strength of 2.4-mm AO locking screw with those ofHerbert screw and 2.0-mm AO cortical screw.

MATERIAL AND METHOD

The studies pemformed by using Instron 4502 to measure the pullout strength in 12 models for each type of the screw. The pullout strength of the 2.4-mm AO locking screw from a corticocancellous bone model was compared with the pullout strength of the Herbert screw from a cancellous bone model and the 2.0-mm AO cortical screw ifom the corticocancellous bone model. The differences in pullout strength between the 2.4-mm AO locking screw and the other two screws were determined by independent t-test.

RESULTS

The pullout strength of the 2.4-mm AO locking screw, Herbert screw and 2.0-mm AO cortical screw were 143.49+46.18 N, 72.83 +/- 16.64 N, and 80.38 +/- 1.42 N, respectively. The pullout strength of2.4-mm AO locking screw was signi2ficantly higher than those ofHerbert screw and 2.0-mm AO cortical screw (p<0.001).

CONCLUSION

According to the recent biomechanical study, the 2.4-mm AO locking screw in the corticocancellous bone model had pullout strength higher than the Herbert screw in the cancellous bone model and the 2.0-mm AO cortical screw in corticocancellous bone model. The 2.4-mm AO locking screw may use instead of headless screw for intra-articular fixation in a specific situation, such as when the headless screw is unavailable.

Massive rotator cuff tear associated with acute traumatic posterior shoulder dislocation: report of two cases and literature review

A massive rotator cuff tear in association with acute traumatic posterior glenohumeral dislocation is rare. To our knowledge, only four documented cases have been reported in the literature. We present two additional cases of such injury secondary to the traffic accident. The first patient had an unsuccessful closed reduction due to the posterior instability while the second developed the profound shoulder weakness following the reduction. From the findings of our cases together with the previous reports, every patient had a unique injury mechanism of high-energy directed axial loading on an outstretched, adducted, and internally rotated arm. The glenohumeral capsule and rotator cuff were uniformly avulsed from the humeral attachment, and the supraspinatus and infraspinatus were always involved. However, the clinical presentations were variable based on the severity of the associated rotator cuff tear. The outcomes of operative treatment in this type of injury with the open repair were favorable.

Flexor pollicis longus injury after corrective osteotomy of distal radius malunion with volar fixed-angle plating: case report and review literature of the flexor tendon injuries after volar plating

Flexor tendon injury is a potential complication after volar plating of distal radius fracture. This article reports a case of flexor pollicis longus tendon rupture after corrective osteotomy of a distal radius malunion with volar fixed-angle plating. Thirty-three cases of flexor tendon injuries after fixed-angle volar plating and eleven cases of flexor tendon injuries after non-fixed-angle volar plating were also reviewed. The clinical presentation, injured tendons, type of the plate, causes of the injuries and preventions of this complication were discussed.

Pullout button suture for the treatment of type IV avulsion of the flexor digitorum profundus tendon: case report

A variety of surgical treatment methods for an avulsion of the flexor digitorum profundus (FDP) from its insertion and simultaneous fracture of the volar base of the distal phalanx, the so-called type IV FDP avulsion had been reported. The need to simultaneously reattach the FDP tendon and fixate the avulsed bony fragment makes the treatment of this injury challenging. The authors described a surgical technique of repair using a pullout suture tied over an external dorsal button without the need for retained hardware.

Alteration of the end-plane angle in press-fit cylindrical stem radial head prosthesis: an in vitro study

PURPOSE

Many studies comparing the morphology of native radial head with the prosthesis have been published. However, there is limited information regarding the postoperative alignment of the articular surface following the radial head replacement. The purpose of this study is to evaluate the alteration of the end-plane angle in the modular radial head prosthesis with a press-fit cementless cylindrical stem.

METHODS

The study used 36 cadaveric radii. The press-fit size prosthesis with cylindrical stem was inserted into each specimen. The end-plane angles of the radial head before and after prosthetic replacement, were measured in coronal and sagittal planes with a digital inclinometer. The data were analyzed by paired t-test.

RESULTS

From paired t-test, there were statistically symmetrical end-plane angles before and after radial head replacement in both coronal and sagittal planes (p-value < 0.01). The mean of radial head end-plane angle alteration in the coronal plane was 3.62° (SD, 2.76°) (range, 0.3°-8.9°). In the sagittal plane, the mean of alteration was 5.85° (SD, 3.56°) degrees (range, 0.3° - 14.2°).

CONCLUSION

The modular radial head prosthesis with cylindrical stem is in vitro able to restore the native end-plane angles of radial heads statistically when used in a press-fit fashion.

A new alternative to quantify finger rotation: angles between the axis of flexed fingers and the axis of third metacarpal bone

OBJECTIVE

To determine whether the proposed angle, formed between the axis of middle and distal phalanges of each of flexed fingers and the axis of the third metacarpal bone was symmetrical between both hands in adult population.

MATERIAL AND METHOD

Thirty-one volunteers (12 males and 19 females) having normal and uninjured hands with an average age of 38 years underwent a fluoroscopic examination of their hands. All volunteers put their hands in a special positioning device that passively held the metacarpophalangeal and proximal interphalangeal joints in full flexion with distal interphalangeal joint in full extension. Fluoroscopic images were then taken and angles were digitally measured.

RESULTS

Mean angles of the flexed index, middle, ring and small fingers compared to the third metacarpal bone were -4.07 (SEM = 1.041), 5.22 (SEM = 0.889), 12.91 (SEM = 1.009) and 23.11 (SEM = 1.370) degrees, respectively. The angles were statistically symmetrical between both hands (p = 0.838, 0.546, 0.620 and 0.641, respectively). The genders had no effect on the symmetry (p > 0.3). The differences between angle of each finger and the angle of the middle finger were also found to be statistically symmetrical.

CONCLUSION

Side-to-side comparison of the angle formed between the axis of flexed fingers and the third metacarpal bone measured from radiographic images can be used as an additional alternative to determine the finger rotation. The angular relationship between each finger with respect to the middle finger can also be used to purposefully reduce x-ray beam projection variation.

Acute true trigger wrist following partial extensor carpi radialis brevis tendon rupture

Triggering in association with movements of the wrist or "true trigger wrist" due to the extensor tendon is rare. There are only few case reports in literature, but none were associated with the acute partial tendon rupture. We present a case of true trigger wrist originating from partial rupture of extensor carpi radialis brevis tendon (ECRB). In contrast to the other reports, the interval between an initial injury and development of triggering was short because the partial tendon rupture was bunching and forming a nodule. The triggering was attributed to the snapping of the nodule under the extensor pollicis longus tendon (EPL).

Triggering of extensor pollicis longus tendon: case report

Triggering of extensor pollicis longus (EPL) tendon is an uncommon phenomenon with a few reports in the previous literature. Because of its rarity, the recommendations for management are sparse. We report a case of triggering EPL tendon secondary to the tendon nodule in a 42-year-old woman treated with the surgical decompression. The intraoperative findings, surgical technique and outcome of this case are described.

The anatomical variation of the lateral femoral cutaneous nerve in relation to the anterior superior iliac spine and the iliac crest

The location of lateral femoral cutaneous nerve (LFCN) in relation to the anterior superior iliac spine (ASIS) and the iliac crest was investigated in 96 embalmed cadaveric specimens. Fifty-six nerves (58.3%) passed medial to the ASIS. Twenty-two nerves (22.9%) passed at the ASIS. Eighteen nerves (18.8%) passed lateral to the ASIS. The LFCN is usually located at 2.1 +/- 0.8 to 3.9 +/- 1.0 cm below the crest in the range of 2-5 cm lateral to the ASIS, respectively. When the anterior iliac crest bone graft harvesting is planned, the anatomical variation in this area should be concerned to reduce the risk of LFCN injury.

Symptomatic flexor carpi radialis brevis: case report

A patient with a flexor carpi radialis brevis (FCRB) is reported. In contrast to all but one previous case, the anomalous FCRB was painful. The FCRB tendon was located in a separate compartment; the tenosynovitis in that compartment was the likely cause of pain. Release of the compartment relieved the symptoms.

Humeral head surface arthroplasty: a case report

Shoulder osteoarthritis is one of the common causes of the shoulder pain. The shoulder arthroplasty is an effective treatment alternative for the patients at advanced disease stage. We presented the first incident case in Thailand who had been diagnosed with primary glenohumeral osteoarthritis and was surgically treated by the humeral head surface arthroplasty. Efficacy and clinical outcomes of this treatment were described.

Measurement of acetabular cup anteversion with the circle theorem

OBJECTIVE

Malposition of the acetabular cup is the major risk factor of dislocation after total hip arthroplasty. Postoperatively, measuring of acetabular cup anteversion is very difficult. The new method for measuring acetabular cup anteversion on the plain radiograph of the hip with one of the circle theorems in the basic geometry was created.

MATERIAL AND METHOD

An all-polyethylene acetabular cup with known angle of radiographic anteversion was mouthed to the pelvic bone. Antero-posterior hip and pelvis radiographs were taken with the cup in randomly 15 different angles of anteversion. These were reviewed by 3 orthopedic residents. All data from 3 observers were collected and examined for the accuracy, inter-observers reliability and intra-observer reliability of this method. Two films (AP radiograph of the hip and the pelvis) method was used for distinguish between anteversion and retroversion.

RESULTS

The measurements of radiographic anteversion have the accuracy of plus or minus 2 degrees. The reliability coefficients of inter-observer variation in the first and second measurements for all definitions of anteversion are high. Pair t-test showed no significant different between value of the first and the second measurements for all definitions in all observers. The intra- and inter-observer variations were 3 degrees or less for all definitions.

CONCLUSION

The Acetabular cup anteversion measurement using the circle theorem iseasily to perform with high accuracy and consistency for all definitions of cup anteversion.

In vitro antimicrobial activity of phramongkutklao hydroxyapatite antibiotic pellet

OBJECTIVE

Assess the antimicrobial activity of Phramongkutklao antibiotic hydroxyapatite pellets in vitro.

MATERIAL AND METHOD

The selected bacteria used in the present study were the standard and drug-resistant strains of Staphylococcus aureus and Pseudomonas aeruginosa, which are the common organisms causing infection in Orthopedics. Phramongkutklao antibiotic hydroxyapatite pellets developed by the Orthopedics Department, Phramongkutklao Hospital contained either Vancomycin, Fosfomycin, or Gentamycin. Each preparation was placed on an agar plate inoculated with each bacterium. The inhibition zones were monitored in 24 hours. Then the pellets were moved onto the new inoculated plate every day for 28 days.

RESULTS

Compared with the control group, Phramongkutklao antibiotic hydroxyapatite pellets had good inhibitory effect against S.aureus. Vancomycin hydroxyapatite pellets were able to maintain their activity for 28 days whereas Gentamycin hydroxyapatite pellets was effective for only three days. Fosfomycin hydroxyapatite pellets could inhibit MSSA for 13 days and MRSA for 25 days. On the contrary, all three Phramongkutklao antibiotic hydroxyapatite pellets had very low efficacy against Paeruginosa.

CONCLUSION

Phramongkutklao antibiotic hydroxyapatite pellets were able to inhibit the growth of S. aureus both MSSA and MRSA while the activity against P. aeruginosa needs to be developed.

Validation of a new surgical procedure for percutaneous scaphoid fixation using intra-operative ultrasound

A new technique for percutaneous fixation of non-displaced scaphoid fractures is described. The technique used pre-operative planning from computed tomography images, registration to intra-operatively acquired three-dimensional ultrasound images, and intra-operative guidance using an optical tracking system. Two stand-alone software applications were developed. The first one was used to determine the surgical plan pre-operatively and the second one was used to guide the surgeon during screw insertion. Laboratory validation of the technique included measurements of the inter-operator and intra-operator variability in the outcome of scaphoid fixation using the proposed procedure, and also included comparison of the performance of this procedure with the conventional percutaneous fixation technique using fluoroscopy. The results showed that the tight accuracy requirements of percutaneous scaphoid fixation were met and that the consistency was superior to the conventional technique.

Ultrasound-guided percutaneous scaphoid pinning: operator variability and comparison with traditional fluoroscopic procedure

This paper reports on pilot laboratory experiments with a recently proposed surgical procedure for percutaneous screw insertion into fractured scaphoid bones using ultrasound guidance. The experiments were intended to determine the operator variability of the procedure and its performance in comparison with a traditional pinning procedure using fluoroscopy. In the proposed procedure, a three-dimensional surface model is created from pre-operative computed tomography images and intra-operatively registered to the patient using ultrasound images. A graphical interface that communicates with an optical camera tracking the surgical tools, guides the surgeon during the procedure in real time. The results of the experiments revealed non-significant differences between operators for the error in the entry location of the drill hole (p=0.90); however, significant differences for the exit location (p<0.05). Comparison with the traditional pinning procedure shows that the outcome of the recently proposed procedure appears to be more consistent.

Management of post-traumatic malunion of fractures of the distal radius

Distal radius malunions are a common cause of patient morbidity. This review of the literature surrounding distal radius malunion covers the demographics, pathologic anatomy, and indications for surgery, surgical techniques, and salvage options. Particular emphasis is placed on subject areas that have not been reviewed as extensively in previous articles, including: intra-articular malunion, computer-assisted techniques, bone graft alternatives, and volar fixed-angle plate osteosynthesis.