The Journal of Hand Surgery (Asian-Pacific Volume)

Background: This purpose of the study was to conduct a systematic review of available literature regarding the association between ulnar variance and outcomes after repair of peripheral traumatic tears of the triangular fibrocartilage complex (TFCC).

Methods: A systematic literature search of the medical literature about peripheral tears of the TFCC was performed. We selected seven studies comparing clinical outcome and ulnar variance in patients with peripheral TFCC tears. We evaluated quality of the articles using both the Structured Effectiveness Quality Evaluation Scale (SEQES) and Sackett’s Level of Evidence (LOE). The outcomes were objective or self-assessment scoring systems for the function of the hand, wrist, or upper extremity.

Results: Seven articles were evaluated. The SEQES scores varied from 19 to 28, with a mean of 23. Five studies reported no association between ulnar variance and clinical outcome, and 2 studies reported an association. The studies reporting no association either excluded or did not mention the cases of unstable distal radioulnar joint (DRUJ).

Conclusions: This systematic review did not demonstrate strong evidence regarding the association between ulnar variance and outcomes after TFCC repair. As most of the studies did not distinguish between capsular and foveal tears which can affect DRUJ stability, further studies looking at this point are necessary to determine whether ulnar shortening osteotomy has an added value for better outcomes after TFCC repair.

Background: Venous thromboembolism (VTE) has been studied in lower extremity fractures but little is known of its relation with upper extremity (UE) fractures. As an often overlooked but serious complication, VTE may compromise patient outcomes.

Methods: Using data on inpatients (aged ≥ 18 years) at a level-I trauma center and patients in the National Surgical Quality Improvement Program database who sustained UE fractures (clavicle, humerus, or radius/ulna) and VTE in the same hospitalization between 2007 and 2014, the authors analyzed data on demographic characteristics, fracture type, VTE location (pulmonary embolism, lower extremity, or UE), VTE onset, polytrauma, operative or nonoperative management, comorbidities, and mortality.

Results: Of 1984 inpatients with UE fractures at 1 instution, 9 experienced VTE on admission, and 17 (15 received thromboprophylaxis) experienced VTE during hospitalization, for an overall VTE rate of 1.3%. VTE occurred most often in patients with fractures of the proximal humerus (3.0%) followed by the clavicle (2.0%), midshaft humerus (1.9%), distal radius/ulna (0.95%), and distal humerus/elbow (0.36%) (p = 0.0035). There were no significant trends in the incidence of PE (p = 0.33) over the study period, but there was a sharp rise since 2011. In the national database, 42 of 11570 (0.36%) patients with UE fracture had VTE, with incidence by fracture location ranging from 0.14% (radius/ulna) to 0.98% (proximal humerus) (p = 0.00001). Predictors were chronic steroid use (odds ratio [OR] = 6.22, p = .030), inpatient status (OR = 4.09, p = .002), and totally disabled functional status (OR = 3.31, p = .021).

Conclusions: VTE incidence was highest following proximal humerus or clavicle fractures and are rarely associated with radius/ulna fractures. There may have been a rise in the incidence of PE since 2007, warranting further investigation.

Background: The Extensor Pollicis Brevis (EPB) is an extrinsic thumb muscle whose main function is extension of the first metacarpophalangeal joint (MCPJ). It is subject to significant anatomical variation and may be absent, vestigial or have an anomalous distal attachment. Clinical examination of EPB is notoriously difficult and no reliable test has yet been described. We propose a novel test for the accurate examination of EPB. We sought to clarify the anatomical variations of EPB and to validate our clinical test using human cadaveric anatomical tests.

Methods: A structured literature review of all human cadaveric anatomical studies describing the attachments of EPB was performed using MEDLINE and Embase with the key words “Extensor Pollicis Brevis”. A cadaveric anatomical study was performed using 18 unembalmed upper limbs. Positive and negative tests were simulated by manipulating the tendons of EPB, Extensor Pollicis Longus (EPL) and Flexor Pollicis Longus (FPL). Changes in tendon tension and joint position were measured and recorded. The EPB anatomy was then determined by dissection.

Results: Anatomical variations were present in the majority of wrists, with only 35% of EPB tendons having a distal attachment to the proximal phalanx alone. EPB was absent in 5% of specimens. There was a significant difference between the change in MCPJ position between a positive (36 degrees; 95% CI 25 to 47 degrees) and negative (19 degrees; 95% CI 14 to 25 degrees) clinical test (p = 0.002).

Conclusions: The functional importance of EPB depends on its congenital architecture in addition to the functional demands of the patient. We report a novel clinical test which is effective in demonstrating the integrity of the EPB. A positive test result is observed when a change in MCPJ position that occurs while the interphalangeal joint is brought into flexion from full thumb extension is 25 degrees or more.

Background: Dupuytren’s disease results in contracted cords in the hand that lead to deformity and disability. Current treatment options include fasciectomy and an injectable, collagenase clostridium histolyticum. No cost comparison studies have been published within the Australian health care environment.

Methods: A retrospective review of all patients treated for Dupuytren’s disease in a major teaching hospital was undertaken to compare the costs of treatment by fasciectomy or collagenase injection.

Results: Eighteen patients underwent fasciectomy and 21 collagenase clostridium histolyticum injections were performed during the study period and were eligible for inclusion under the review criteria. Of the 39 patients, 36 were male and 3 were female with an average age 66.4 years (50–85). Twenty-five digits were treated by fasciectomy in 18 patients, and 23 digits were treated by collagenase in 21 patients. The fasciectomy group attended an average 9.2 visits (5–22), incurring an average costing of US$5738.12 per patient ($3181.18–$9618.10). The collagenase group attended an average 3.8 visits (3–8), incurring an average costing of US$2076.83 per patient ($1842.24–$3929.57).

Conclusions: Collagenase treatment of Dupuytren’s contracture represents a significant reduction in cost relative to fasciectomy, with 64% savings, length of follow up and number of visits. This is a similar finding to studies in other countries.

Background: Arthroscopy is a widely used minimally invasive technique. Nevertheless, no report describes the arthroscopic anatomy of the proximal interphalangeal (PIP) joint for portal creation. To facilitate arthroscopy, this study elucidated the anatomy of the lateral bands of the extensor mechanism and collateral ligaments of PIP joints.

Methods: A total of 39 fingers from the right hands of 10 cadavers (4 males, 6 females) were evaluated in this study. We defined the extension line from the proximal interphalangeal volar crease as the C-line. We also defined an imaginary line along the distal edge of the proximal phalanx, which is parallel to the C-line, as the J-line. The distance between J-line and C-line was measured. On the C-line and J-line, we measured the following: from the dorsal skin to the lateral edge of the lateral band (LB), the dorsal edge of the collateral ligament (CL) and from the lateral band and the collateral ligament (D), the width of the finger (W). The finger half-width (M) was measured on the J-line. Comparison between the digits and comparison between radial and ulnar distance were measured and statistical analysis was performed.

Results: All PIP joint spaces were distal from the C-line, except for one ring finger. The average distances between the J-line and C-line were 1.8–3.2 mm. On the C-line, only 11 cases (14.1%) showed an interval between the lateral bands and the collateral ligaments, but, on the J-line 72, cases (92.3%) had such an interval. The interval was located 1.6–2.9 mm in a dorsal direction from the midlateral on the J-line.

Conclusions: Portal creation at the J-line is safer than at the C-line. This study revealed that safe portals for arthroscopy of the PIP joint are 2 mm dorsal to the midlateral line of the finger on the J-line.

Background: The terminal phalanx of the fingers carries the attachment of the Flexor Digitorum Profundus (FDP) on the volar surface and the extensor on the dorsal surface. Avulsion of these tendons has traditionally been repaired with pull-through sutures. Recently, bone anchor sutures have been found to be of comparable biomechanical strength but with the added advantage of technical ease and fewer complications. However, the dimensions of the bone, at the site of insertion of the anchors, have never been studied.

Methods: Following some cases of penetration of the dorsal cortex by the anchors, we measured the antero-posterior dimensions of the terminal phalanx in 251 digits from plain radiographs and compared these with the dimensions of the commonly used bone anchors. We also compared male and female digits.

Results: The anchors were oversized in 76% of index, 78% of ring and 100% of little fingers in the female population and in 49%, 44% and 97% of index, ring and little fingers respectively in the male population.

Conclusions: This analysis of bone dimensions can be a useful guide to surgeons in choosing the appropriate implant for flexor tendon avulsions.

Background: The objective was to quantify joint laxity in healthy volunteers by measuring the passive axial rotation of the trapeziometacarpal joint using the axial rotation test.

Methods: Eighty volunteers (34 men and 46 women) were subjected to the axial rotation shear test and the degree of total rotational motion (TRM) was assessed. Volunteers were divided into Group I with a range of 18–50 years old and Group II for 51 years and older. Statistical analysis was performed.

Results: The average TRM in Group I was 32.3 mm for women, and 27.4 mm, for men (p = 0.04). The average TRM in women of Groups I and II, was 32.3 and 21.6 mm respectively, (p < 0.001). The average TRM in men of Groups I and II, was 27.4 and 19.4 mm (p < 0.001). In Group II the average TRM of women was 21.6 mm, and for men was 19.4 mm, which was not significantly different.

Conclusions: Young women have greater degree of rotational laxity in the TM joint compared to men of the same age group and to older women. The axial rotation test can quantify the degree of rotational laxity of the TM joint.

Background: To identify the time course for efficacy of corticosteroid injections in the treatment of trigger finger.

Methods: A prospective single-center observational study was conducted, consisting of 38 patients with 41 trigger digits that were injected. Enrolled patients completed an initial Disabilities of the Arm, Shoulder, and Hand (DASH) questionnaire to determine the severity of their symptoms. Following the injection, patients were contacted at scheduled time points for up to 12 weeks to determine if, and when, objective resolution of symptoms occurred. Patients who received additional treatment, such as a second injection or surgery, and those who did not have objective relief of symptoms by 12 weeks were classified as failed. Upon symptom resolution or injection failure, patients were given a DASH exit questionnaire.

Results: 30 of 41 injected trigger digits resolved and 11 failed treatment with a single corticosteroid injection. The latest that any study participant experienced resolution of symptoms was 69 days. At 38 days, the rate of resolution of the study population slowed significantly.

Conclusions: Although symptomatic resolution of trigger finger from a single corticosteroid injection can occur early on, a follow-up of 4 weeks (28 days) does not allow enough time for symptom resolution. The earliest a surgeon and patient should consider a secondary treatment is at 38 days. After 69 days without resolution, both surgeon and patient can be confident that further treatment is needed.

Background: The finding of pseudomeningocele from cervical myelogram is widely accepted as a pathognomonic sign for diagnosing root avulsion in brachial plexus injury. In general, motor power in this setting should be absent. However, in clinical practice, we observed that motor power in some patients was still preserved. The objective of this study is to evaluate the accuracy of pseudomeningocele from cervical myelogram for predicting root avulsion in brachial plexus injury.

Methods: We retrospectively reviewed 201 patients with brachial plexus injury from 2007–2011. Four patients were excluded due to open wound injury. Motor power of the key muscle of each nerve root was evaluated by skilled hand surgeons. All cervical myelogram was interpreted by radiologists. Sensitivities, specificities, positive predictive values and negative predictive values were calculated with 95% confidence interval.

Results: Thirty and 29% of pseudomeningocele occurred at C7 and C8 level, respectively. The sensitivity of pseudomeningocele of each root from C5 to T1 was low (range, 10–62%). The specificity was high only at C5 (91%) and T1 (96.2%). Over 20% of patients with pseudomeningocele at C6–8 levels had some motor function. The initial muscle power of these patients was M1 or M2 and 70% of them recovered to at least M3 at the final follow-up.

Conclusions: Pseudomeningocele is not an absolute sign for diagnosing of root avulsion in brachial plexus injury due to its high false positive rate when compared with preoperative motor function of each root. Careful examination of the key muscle of each root is extremely crucial to prevent unnecessary operation on that cervical nerve root.

Background: The Motec cementless modular metal-on-metal ball-and-socket wrist arthroplasty is an implant with promising intermediate results. An alternative to primary wrist fusion, total wrist arthroplasty is an option for active patients, who wish to retain their wrist function. It is indicated in cases of degenerative osteoarthritis, post-traumatic arthritis and rheumatoid (inflammatory) arthritis.

Methods: A prospective review of patient demographics, pre and post-operative Disabilities of the Arm Shoulder and Hand (DASH), MAYO scores, range of movements and grip strengths. All complications in follow up were recorded across the 4 year period.

Results: 25 implants on 23 patients over 5.5 years, mean age 61; 8 females and 15 male. 10 patients with SLAC, 3 SNAC, 5 inflammatory and 7 patients with generalized osteoarthritis. The patients showed significant improvements of MAYO and DASH scores post-operatively, as well as the flexion/extension arc and grip strengths. There was just one case of implant loosening- the radial screw after a wound infection, which was revised with a longer screw. Two implants were converted to Motec fusion due to pain. One implant was dislocated and relocated. The remaining patients have had good wrist function. Only 6 patients were unable to return to work.

Conclusions: Similar to published studies, this series shows the Motec implant to be a good motion preserving alternative to total wrist fusion.

Background: Purulent musculoskeletal infections often require surgical debridement and drainage. However, when the infection is extensive or involving multiple layers of tissues, maintaining drainage of the involved spaces can be difficult, even with the application of vacuum-assisted closure (VAC) therapy. Wide exposure and aggressive debridement is often required for such cases, which in turn may complicate wound coverage.

Methods: A retrospective review was performed for 16 patients with musculoskeletal infections treated surgically. The diagnosis for the patients consisted of necrotizing fasciitis, large soft tissue abscess, peri-hardware abscess, infected compartment syndrome, emphysematous osteomyelitis, and gas gangrene of diabetic foot. We minimized the incision and resection for debridement and drainage, and instead we placed multiple foam pieces between the tissues involved with VAC, to maintain drainage of the hidden spaces with negative pressure.

Results: Infection was successfully controlled in all cases. The mean duration of VAC treatment was 16.1 days (range, 5–36) and the mean number of VAC changes was 5.1 (range, 1–13). Primary wound closure was achieved in 11 cases, while skin grafts were used to cover the remaining five cases, which consisted of necrotizing fasciitis, infected compartment syndrome, and diabetic foot gas gangrene. No complications specifically associated with VAC therapy were observed.

Conclusions: VAC using multiple foam pieces for hidden space drainage appears to be effective for infection control. It is helpful for minimizing exposure and resection for drainage and debridement, although subsequent reduction of the necessity or the level of wound coverage should further be investigated.

Background: Arthrodesis of the distal interphalangeal (DIP) joint reliably improves symptomatic arthritis. A range of successful surgical techniques including tension band wiring, plate fixation and headless compression screws have been described and produce stable painless unions. For best functional outcome, the fusion angle should be between 10 and 61 degrees. In the past, it has been difficult to achieve more than 10 degrees of flexion with a headless compression screw. Higher fusion angles have been reported using tension band wiring techniques. However, metalwork prominence is a common problem and may require revision surgery to rectify this. Headless compression screws are reported to cause iatrogenic fractures due to the size of the screw relative to the small diameter of the phalanx. This case series achieves an angle of up to 35 degrees with a good functional outcome.

Methods: Open fusion of the DIP joint with a headless cannulated compression screw, of 2.2 mm in diameter, was undertaken in fifteen digits. Patients received standard departmental follow up to radiographic union. Patients self-reported function using the Michigan Hand Questionnaire post operatively. The fusion angles achieved were assessed on postoperative radiographs.

Results: All patients went on to a stable union without any patients requiring revision surgery as a result of fracture or protrusion of metalwork. Complications were observed in two patients which included one superficial infection (n = 1) and a discomfort requiring removal of metalwork (n = 1). Functional scores measured post operatively showed favourable outcomes.

Conclusions: In this series, successful fusions of the DIP joints, at an angle up to 35 degrees were achieved using small diameter headless compression screws, which provided benefits including early mobilization and favourable functional outcome scores.

Background: There are several methods for measuring edema of the hand. While the volumetric techniques, finger circumference measurement, and figure-of-eight techniques have undergone extensive psychometric testing, alternative methods of measuring hand size, such as circumferential finger size determination using a ring gauge (ring gauge method; RGM) and tape measurement of hand girth taken along the distal palmar crease (metacarpal head tape measure method; MHTM), have not. This study's aim is to examine the reliability and validity of the RGM and the MHTM.

Methods: In this cross-sectional study, two examiners measured 22 hands in 22 patients with hand edema using the RGM and the MHTM 3 times each to determine intra- and inter-tester reliability. The validity of each method was established using the finger circumference measurement and figure-of-eight method, respectively.

Results: The intra-class correlation coefficient (ICC) obtained for intra-tester reliability was 0.99–0.98 for both methods. ICCs for inter-tester reliability were 0.97–0.98 for the RGM and 0.98 for the MHTM. Pearson product-moment correlation values between the RGM and finger circumference measurement were 0.92–0.96, while those between the MHTM and figure-of-eight method were 0.84–0.90.

Conclusions: The RGM and the MHTM are reliable and valid evaluation tools for the assessment of hand size.

Background: This study aimed to investigate whether the distance between the radial nerve and rotational center of the elbow joint when observing from the lateral surface of the humerus changes according to passive elbow joint flexion for safe external fixation with a hinged fixator of the elbow joint.

Methods: Twenty fresh-frozen cadaveric arms were dissected. The points where the radial nerve crosses over the posterior aspect of the humerus, crosses through the lateral center, and crosses over the anterior aspect of the humerus were defined in the lateral view of the elbow joint, using fluoroscopy, as R1, R2, and R3, respectively. The distances between the rotational center and each point on the radial nerve were measured when the flexion angle of the elbow joint was 10°, 50°, 90°, and 130°.

Results: The distances between the rotational center and R1, R2, and R3 were 118 mm, 94 mm, and 65 mm, respectively, when the flexion angle was 10°; 112 mm, 93 mm, and 74 mm, respectively, for 50°; 108 mm, 93 mm, and 77 mm, respectively, for 90°; and 103 mm, 94 mm, and 83 mm, respectively, for 130°. The distance between the rotational center and R2 was constant regardless of the flexion angle. With elbow joint extension, the distances between R1 and R3 increased; the safe zone, a region where the radial nerve would not be located on the humerus, was the smallest in extension. When the elbow joint was flexed, the distances between R1 and R3 decreased; the safe zone was the largest in flexion.

Conclusions: This study showed that the radial nerve location on the humerus varied based on the flexion angle of the elbow joint; the safe zone may change. A half-pin can be likely inserted safely, avoiding the elbow joint extension position.

A 16-year-old man sustained a minor penetrating injury to his forearm, resulting in pseudoaneurysm formation that caused acute compartment syndrome with muscle contracture. Surgical treatment, including fasciotomy, evacuation of the hematoma and aneurysmectomy, followed by intensive hand therapy provided a successful outcome. Traumatic pseudoaneurysm after penetrating injury is a rare cause of acute forearm compartment syndrome. Although minor penetrating injuries tend to be underestimated, this type of injury can cause subsequent serious pathological conditions.

A 20-year-old male has presented with mild numbness and tingling sensation at 4, 5^th finger of his left hand. Simple radiograph and MRI images revealed bony mass at medial joint space of ulno-humeral joint. After surgical exploration, we found that there were two cause of ulnar nerve irritation symptom. Fixed ulnar nerve position at anterior aspect to medial condyle with deficiency of nerve gliding was one cause, and friction irritation around bony mass was another. It is rarely reported that ulnar nerve always travels to the anterior side of the medial condyle of the elbow, and there are no cases involving skeletal variation. In this case, the ulnar nerve may be penetrated while forming an anterior medial portal around elbow joint. It is important to know the path of the ulnar nerves very carefully through imaging and physical examination when there is a bony variant in the elbow joint.

Arthroscopic dorsal wrist ganglionectomy is demonstrably a safe procedure with recurrence rates comparable to open surgery. We present a patient with wrist pain following arthroscopic ganglion excision. MRI and arthroscopic findings showed a large dorsal capsular defect, synovial fistula to the fourth extensor compartment, and dorsal radiocarpal ligament resection. Ligament reconstruction and capsular imbrication resolved her symptoms. We postulate that this complication resulted from a large capsular resection. Because we feel that it can be difficult to judge the size of the debridement through an arthroscope, the need for adequate capsular resection in dorsal wrist ganglionectomy needs to be balanced by consideration of potential complications from more aggressive capsular debridement, and thus we feel that capsular resection should be limited to no more than 1 cm².

A 15-year-old male patient presented with difficulty extending his right thumb due to subluxation of the extensor pollicis longus (EPL) tendon. Physical examination showed that active motion of the thumb’s metacarpophalangeal (MP) joint was 76° in flexion and -58° in extension. During active extension, the EPL tendon shifted onto the ulnar aspect of the MP joint, and the extensor pollicis brevis (EPB) tendon shifted onto the central dorsal course of the MP joint. After repositioning by adducting the thumb into the palm to extend the MP joint (dynamic tenodesis effect), active extension of the MP joint increased to -12°. Corrective surgery was performed under local anesthesia and radial sensory nerve block. Following plication of the attenuated dorsal capsule and sagittal band between the EPB and EPL, we confirmed that the patient could flex and extend the thumb smoothly. One year postoperatively, the extension deficit of the MP joint had not recurred.

In severe carpal tunnel syndrome a continuum of neural changes takes place depending on the degree and duration of the compression, beginning with breakdown of the blood-nerve barrier, followed by endoneurial oedema and, subsequently, perineurial thickening and ischemia. Persisting chronic compression will eventually result in axonal degeneration. We report a case of longstanding carpal tunnel syndrome with amyloid deposits and the unusual intraoperative ‘Austrian flag’ sign.

A liposarcoma is extremely rare in the digits. A 73-year-old woman was diagnosed with a lipoma in her middle finger 10 years ago. As this tumor increased in size and presented with imaging findings that were atypical of lipomas, careful marginal resection biopsy outside the pseudo-capsule was performed, and the tumor was diagnosed as a well-differentiated liposarcoma. At the 5-year follow-up, the patient showed no evidence of local recurrence or metastasis, with no loss of hand function. The findings from this case suggest that even for a lipomatous tumor in the digits, further imaging examination and resection biopsy should be considered if the tumor presents with features that are atypical of lipomas.

Early active mobilization after hand surgery is extremely important for preventing scar tissue and adhesion. We examined four patients for whom continuous peripheral nerve blocks (CPNB) were used during and after hand surgery. This method was used for three median nerves and one ulnar nerve. A 2-cm incision was made at distal one-third of the forearm with local analgesia. The catheter tip was placed in the distal one-fourth of the forearm, and the hand surgery was begun. Early active mobilization and the self-rehabilitation exercise started immediately after the operation. The VAS scores during exercise were 0–2 (mean: 1.3); pain was controlled sufficiently. Regarding ROM, excellent results were obtained for tenolysis, with good results for arthrolysis. No infection or postoperative nerve compression was found. This method, using CPNB with a portable infusion pump, is effective and safe for use at home for postoperative pain control.

Unidirectional porous β-tricalcium phosphate (UDPTCP; Affinos^®, Kuraray, Tokyo, Japan) has been in clinical use since 2015. Animal studies have confirmed the excellent potential of UDPTCP with regard to bone formation and material absorption. We present the first three clinical cases using UDPTCP as a bone substitute after curettage of benign bone tumors of the hand. All three patients were males, 29-, 30- and 81-years-old, two having a diagnosis of enchondroma and the other, a bone ganglion, with a pathological fracture identified in one case. Over a mean follow-up of 10 months, all patients achieved satisfactory clinical result, with no adverse events of UDPTCP noted. Radiographic evidence of good bone formation and material absorption was observable over the postoperative course. UDPTCP provided satisfactory clinical results, with good biocompatibility and fast resorption characteristics. Therefore, UDPTCP could provide a safe and reliable filling substitute for bone defects following curettage of small bone tumors.

Avulsion fracture of the volar base of the distal phalanx is a rare injury. Zone 1 flexor tendon injuries can be treated with either internal or external fixation techniques. Pull-out suture repairs are often used for FDP tendon avulsion injuries. However, the pull out suture technique is associated with a number of well documented complications including nail bed injury and pressure necrosis. Despite the variety of techniques available for the repair of acute distal zone 1 flexor tendon injuries, no one technique has proven to be superior to all others. We address our experience with treatment of FDP avulsion injuries using suture anchor and miniscrew. Our technique supplements the suture anchor technique, which often causes a lack of strength, with an additional miniscrew. We introduce two cases of combined method using both suture anchor and miniscrew for treatment of FDP avulsion injuries.

We describe our injection method for Collagenase Clostridium Histolyticum using a medical silicone tube after determining the optimal depth by ultrasonography. This procedure adjusts the exposed needle length to the planned injection depth by placing a sterilized silicone tube over the needle. The restricted depth provides not only precise injection into the middle of the cords but also avoids needle tip migration through the cord and into the vital structures, which prevents possible complications. This method is safe and simple.