Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Ari Pajala is active.

Publication


Featured researches published by Ari Pajala.


Journal of Orthopaedic Research | 2002

Increased content of type III collagen at the rupture site of human Achilles tendon.

Heidi Eriksen; Ari Pajala; Juhana Leppilahti; Juha Risteli

We compared the type I and III collagen amounts and cross‐linked telopeptides at the rupture site and two other sites of the same tendon. Tendon samples of ten individuals with total Achilles tendon rupture and six healthy cadavers were collected. The newly synthesized type I and III procollagens were assessed by extracting the soluble propeptides PINP, PICP and PIIINP. The insoluble matrix was solubilized by heat denaturation and trypsin digestion. Hydroxyproline, the cross‐linked telopeptide structures of type I (ICTP and SP 4) and III collagens (IIINTP) and the degradation product of type III collagen (tryptic PIIINP) were measured from the digests.


American Journal of Sports Medicine | 2007

Achilles Tendon Elongation After Rupture Repair A Randomized Comparison of 2 Postoperative Regimens

Jarmo Kangas; Ari Pajala; Pasi Ohtonen; Juhana Leppilahti

Background A few prospective controlled trials comparing early functional rehabilitation after Achilles tendon repair and non-operative immobilization have been reported. Hypotheses There is no difference in Achilles tendon elongation between early motion and immobilization after Achilles tendon repair. Tendon elongation does not correlate with the clinical outcome. Study Design Randomized clinical trial; Level of evidence, 2. Methods Fifty patients with acute Achilles tendon rupture were randomized postoperatively to receive either early movement of the ankle between neutral and plantar flexion in a brace for 6 weeks or immobilization in tension using a below-knee cast with the ankle in a neutral position for 6 weeks. Full weightbearing was allowed after 3 weeks in both groups. Standardized radiographs to measure previously placed radiographic markers were taken on the first day postoperatively and at 1, 3, 6, 12, 24 weeks postoperatively, with the final radiograph a mean of 60 (SD, 6.4) weeks postoperatively. The outcome was assessed at the 3-month and final checkups by the clinical scoring method described by Leppilahti et al and included subjective factors and objective factors. Results Tendon elongation occurred in both groups but was somewhat less in the early motion group (median 2 mm in the early motion group vs median 5 mm in the cast group a mean of 60 weeks postoperatively, P = .054). The elongation curves first rose and then slowly fell in both groups. The patients who had less elongation achieved a better clinical outcome (ρ= -.42, P = .017). Tendon elongation did not correlate significantly with age, body mass index, or isokinetic peak torques. Conclusion Achilles tendon elongation was somewhat less in the early motion group and correlated with the clinical outcome scores. We recommend early functional postoperative treatment after Achilles rupture repair.


Journal of Bone and Joint Surgery, American Volume | 2002

Rerupture and deep infection following treatment of total Achilles tendon rupture

Ari Pajala; Jarmo Kangas; Pasi Ohtonen; Juhana Leppilahti

Background: The incidence of total Achilles tendon rupture has increased, but we are not aware of any reports on the incidence of reruptures or deep infections following treatment. The outcome after successful treatment is good, but that after complications has not been well documented.Methods: A group of 409 patients with a complete Achilles tendon rupture was treated at a university hospital orthopaedic unit between 1979 and 2000. Twenty-three reruptures (prevalence, 5.6%) and nine deep infections (prevalence, 2.2%) occurred in twenty-nine patients. We retrospectively reviewed the records of these patients to determine the overall incidence of ruptures, reruptures, and deep infections and to record the known risk factors for these major complications. We analyzed the final clinical outcome for twelve patients with a rerupture and seven patients with a deep infection at a mean of 4.1 years after the initial treatment.Results: The annual incidence of reruptures (per 100,000 inhabitants) increased from 0.25 in 1979-1990 to 1.0 in 1991-2000, and that of deep infections increased from 0 in the 1980s to 0.63 in the 1990s. The ratio of complications to primary ruptures did not change. The patients with deep infections were significantly older, received corticosteroid medication more often, had sustained the tendon injury during everyday activities more often, and had a longer delay before treatment than the patients with simple reruptures. At 4.1 years after the primary treatment, eight of twelve patients in the rerupture group had a satisfactory clinical outcome and the overall average isokinetic plantar flexion strength deficit in that group was only 10%. In contrast, two of the patients in the infection group had a fair clinical outcome and five had a poor outcome, and the average isokinetic plantar flexion strength deficit in that group was 35%.Conclusions: The incidence of Achilles tendon reruptures and deep infections has increased. The outcome is satisfactory after a simple rerupture without infection, but the results after a deep infection are often devastating.


Journal of Trauma-injury Infection and Critical Care | 2003

Early functional treatment versus early immobilization in tension of the musculotendinous unit after Achilles rupture repair: a prospective, randomized, clinical study.

Jarmo Kangas; Ari Pajala; Pertti Siira; Martti Hämäläinen; Juhana Leppilahti

BACKGROUND The aim of our prospective, randomized, clinical study was to compare two postoperative regimens after Achilles rupture repair and determine whether early functional treatment will give a better result than early immobilization in tension of the musculotendinous unit. METHODS Fifty patients with acute Achilles tendon rupture were randomized postoperatively to receive either early movement of the ankle between neutral and plantar flexion in a brace for 6 weeks or Achilles tendon immobilization in tension using a below-knee cast with the ankle in a neutral position for 6 weeks. Full weight bearing was allowed after 3 weeks in both groups. The patients were assessed clinically at 1, 3, 6, 12, and 24 weeks, and the last control visit took place at a mean of 60 (SD 6.4) weeks postoperatively. RESULTS The isokinetic calf muscle strength scores were excellent in 56%, good in 32%, fair in 8%, and poor in 4% of the patients in the early motion group at the last control checkup; whereas the scores in the cast group were excellent in 29%, good in 50%, and fair in 21% of the patients. The ankle performance scores were excellent or good in 88%, fair in 4%, and poor in 8% of the patients in the early motion group, whereas the scores in the cast group were excellent or good in 92% and fair in 8% of the patients. At 3 months and at the last control checkup, no significant differences were seen between the two groups with regard to pain, stiffness, subjective calf muscle weakness, footwear restrictions, range of ankle motion, isokinetic calf muscle strength, or overall outcome. The complications included one rerupture in the early motion group and one deep infection and two reruptures in the cast group. Deep infection and the rerupture in the cast group occurred in the same patient. The outcome of the complications was good in two cases and poor in one. CONCLUSION The isokinetic calf muscle strength results were somewhat better in the early motion group, whereas the other outcome results obtained in the two groups of patients were very similar. We recommend early functional postoperative treatment after Achilles rupture repair for athletes and well-motivated patients and for less-motivated patients and nonathletes.


Biomaterials | 2004

Biocompatibility and strength properties of nitinol shape memory alloy suture in rabbit tendon.

Sauli Kujala; Ari Pajala; Matti Kallioinen; Antti Pramila; Juha Tuukkanen; J. Ryhänen

Nitinol (NiTi) is a promising new tendon suture material with good strength, easy handling and good super-elastic properties. NiTi sutures were implanted for biocompatibility testing into the right medial gastrocnemius tendon in 15 rabbits for 2, 6 and 12 weeks. Additional sutures were implanted in subcutaneous tissue for strength measurements in order to determine the effect of implantation on strength properties of NiTi suture material. Braided polyester sutures (Ethibond) of approximately the same diameter were used as control. Encapsulating membrane formation around the sutures was minimal in the case of both materials. The breaking load of NiTi was significantly greater compared to braided polyester. Implantation did not affect the strength properties of either material.


Journal of Bone and Joint Surgery, American Volume | 2009

Augmented compared with nonaugmented surgical repair of a fresh total Achilles tendon rupture. A prospective randomized study.

Ari Pajala; Jarmo Kangas; Pertti Siira; Pasi Ohtonen; Juhana Leppilahti

BACKGROUND Augmented and nonaugmented techniques have been used for the operative repair of a fresh complete Achilles tendon rupture. Augmented techniques have been favored for their stronger pullout strengths but have been avoided because of the risk of wound complications. If proven to be equally good, the nonaugmented technique would be the method of choice. In the present study, we hypothesized that augmentation with a down-turned gastrocnemius fascia flap would not provide better results than would end-to-end suture repair with use of the Krackow locking loop surgical technique. METHODS Sixty patients with an acute Achilles tendon rupture were randomized preoperatively to receive end-to-end suture repair with use of the Krackow locking loop technique either without augmentation (simple repair group) or with a down-turned gastrocnemius fascia flap as described by Silfverskiöld (augmented repair group). A brace allowed free active plantar flexion of the ankle postoperatively, whereas dorsiflexion was restricted to neutral for the first three weeks. Weight-bearing was limited for six weeks. The follow-up period was one year, and the patients were evaluated in terms of clinical measurements, an outcome score, isokinetic calf muscle performance tests, and tendon elongation measurements. RESULTS The mean operative time was twenty-five minutes longer and the incision was 7 cm longer in the augmented repair group as compared with the simple repair group (p < 0.001 for both). In the simple repair group, the overall ankle score was excellent for nineteen patients (63%) and good for eight patients (27%) and three patients (10%) had an early failure (all because of rerupture). In the augmented repair group, the ankle score was excellent for fourteen patients (56%) and good for six patients (24%) and five patients (20%) had a failure because of rerupture (three) or deep infection (two). The difference between the groups with regard to the overall result was not significant (p = 0.68). In the simple repair group the isokinetic calf muscle strength score was excellent for eleven patients (37%), good for fourteen patients (47%), and fair for two patients (7%), with three patients (10%) having a failure, whereas in the augmented repair group the score was excellent for nine patients (36%), good for seven patients (28%), fair for three patients (12%), and poor for one patient (4%), with five patients (20%) having an early failure. Achilles tendon elongation occurred in both groups, and elongation correlated significantly with isokinetic peak torque deficits (rho = 0.64, p = 0.001) and isometric strength deficits (rho = 0.48, p = 0.026) in the simple repair group. No significant differences were seen between the two groups at the three-month and twelve-month checkups with regard to pain, stiffness, subjective calf muscle weakness, footwear restrictions, range of ankle motion, overall outcome, isokinetic calf muscle strength, mean peak work-displacement relationships, or tendon elongation. CONCLUSIONS Augmented repair of a fresh total Achilles tendon rupture does not have any advantage over simple end-to-end repair.


Knee | 2011

Unicompartmental knee arthroplasties implanted for osteoarthritis with partial loss of joint space have high re-operation rates

Tuukka Niinimäki; David W. Murray; Juha Partanen; Ari Pajala; Juhana Leppilahti

The indications and contraindications for unicompartmental knee arthroplasty (UKA) are controversial. The aim of the study was to determine the risk factors for re-operation in our practice. A series of 113 medial UKAs with mean follow-up of 63 months were reviewed retrospectively. Pre-operatively all knees had radiographic or arthroscopic evidence of severe cartilage damage. The re-operation rate was not related to age, gender, arthroscopic finding or body mass index. It was related to the joint space on pre-operative standing weight bearing radiographs taken in extension. The re-operation rate was 6 (95% CI 2.1-17, P<0.001) times higher when the thickness of the pre-operative medial joint space was >2 mm rather than ≤2 mm. It was 8 (95% CI 2.8-22.5, P<0.001) times higher when the thickness of the pre-operative medial space was >40% of the thickness of the lateral space. The ratio of pre-operative joint spaces has a greater influence on revision rate than the absolute measurement and is independent of radiographic magnification or the patients normal cartilage thickness. We therefore recommend that, in medial knee osteoarthritis, UKA should only be used if the pre-operative medial joint space on standing radiographs is ≤40% of the lateral joint space, even if severe cartilage damage is seen arthroscopically.


Journal of Bone and Joint Surgery, American Volume | 2016

Augmented Compared with Nonaugmented Surgical Repair After Total Achilles Rupture: Results of a Prospective Randomized Trial with Thirteen or More Years of Follow-up.

Juuso Heikkinen; Iikka Lantto; Tapio Flinkkilä; Pasi Ohtonen; Ari Pajala; Pertti Siira; Juhana Leppilahti

BACKGROUND This prospective randomized trial with a mean fourteen-year follow-up compared simple end-to-end repair with fascial flap-augmented repair for acute Achilles tendon ruptures. METHODS From 1998 to 2001, sixty patients with acute Achilles tendon rupture were randomized to receive simple end-to-end repair or augmented repair; both groups were treated with postoperative bracing allowing free active plantar flexion. After a follow-up of thirteen years or more, fifty-five patients (twenty-eight in the nonaugmented-repair group and twenty-seven in the augmented-repair group) were reexamined. Outcome measures included the Leppilahti Achilles tendon score, isokinetic plantar flexion strength (peak torque and the work-displacement deficit at 10° intervals over the ankle range of motion), tendon elongation, and the RAND 36-item health survey. RESULTS After a mean of fourteen years of follow-up, the mean Leppilahti score was 87.1 points for the nonaugmented repairs and 91.5 points for the augmented repairs, with a mean difference of 4.3 points (95% confidence interval [CI], -0.1 to 8.8 points). The surgical technique did not have an impact on strength parameters, with a mean peak torque of 112.6 Nm after the nonaugmented repairs and 107.3 Nm after the augmented repairs (mean difference, 5.3 Nm [95% CI, -22.2 to 11.6 Nm]) and a median work-displacement deficit of 6.7% to 20.3% after the nonaugmented repairs and 12.8% to 18.0% after the augmented repairs (p = 0.9). Strength did not significantly change between the twelve-month and fourteen-year follow-up examinations. At a mean of fourteen years, the injured side showed a 12.2% to 18.0% median work-displacement deficit compared with the unaffected side (p < 0.001). RAND-36 scores indicated no between-group difference in health domains. CONCLUSIONS Augmented repair of total Achilles tendon ruptures provided no advantage over simple end-to-end repair. Achilles tendon ruptures result in a permanent calf muscle strength deficit, but its clinical relevance remains unclear. LEVEL OF EVIDENCE Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.


Histology and Histopathology | 2009

Tenascin-C and type I and III collagen expression in total Achilles tendon rupture. An immunohistochemical study

Ari Pajala; Jukka Melkko; Juhana Leppilahti; Pasi Ohtonen; Ylermi Soini; Juha Risteli


Injury-international Journal of The Care of The Injured | 2005

Salvage of humeral shaft nonunion with cortical thinning after failed intramedullary nailing using Ilizarov's technique A report of seven cases

Tapio Flinkkilä; Jukka Ristiniemi; Ari Pajala; Martti Hämäläinen

Collaboration


Dive into the Ari Pajala's collaboration.

Top Co-Authors

Avatar
Top Co-Authors

Avatar

Pasi Ohtonen

Oulu University Hospital

View shared research outputs
Top Co-Authors

Avatar

Jarmo Kangas

Oulu University Hospital

View shared research outputs
Top Co-Authors

Avatar

Pertti Siira

Oulu University Hospital

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Iikka Lantto

Oulu University Hospital

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Researchain Logo
Decentralizing Knowledge