Modified Mason-Allen technique is described for arthroscopic rotator cuff repair. It combines vertical simple sutures for strength with a horizontal mattress suture to act as a "rip-stop stitch". This technique provides high fixation strength, minimal gap formation, and maintains mechanical stability until tendon healing. A case report demonstrates the technique used to repair a partial supraspinatus tendon tear, with the patient showing functional improvement post-operatively. The Modified Mason-Allen technique offers biomechanical and clinical outcomes comparable to double-row repair, but with lower cost and use for partial-full thickness tears.

1. Modified Mason - Allen
Technique for RTC Repair
July - Oct 2019
by Tran Khoi Luan, M.D at
Division of Shoulder Surgery & Sports Medicine
Department of Orthopedic Surgery
SNUBH

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Introduction
Trainee
Name: Trần Khôi Luân
Department: Upper Extremity in Military
Hospital 175
Training Area: Shoulder Surgery
Advisory Professors:
• Prof. Joo Han Oh
• Prof. Hyeon Jang Jeong

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RTC pathology: common cause of shoulder pain, age-related
Arthroscopic treatment: markedly improved
Suture technique goals
• Biomechanics profile
▪ High fixation strength
▪ Minimal gap formation & tendon strangulation
▪ Mechanical stability until tendon healing
• Anatomical footprint restore
Outcomes: functional & structural
Background

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• Combination of:
▪ Vertical simple sutures:
main holding power
▪ horizontal mattress: “rip
stop stich”
• Reduce sutures cutting out
• Commonly used in open RTC
repair
Modified Mason-Allen Technique
faculty.washington.edu

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Case Report: SST (R5)
• Male, 45 y.o
• History: Rt shoulder pain, 4 y.a
• Physical exam:
• Pain VAS: 5
• Jobe’s test (+)
• Impingement (+)
• ROM: intact
• MRI
• SST: high grade partial tear,
retraction 8.32 mm, AP
dimension 8.27 mm
• Acromion: thickness 9.5mm,
heel type spur at Cor plane.
Patient information

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Case Report: SST (R5)
• Subacromial decompression:
bursectomy (SA-SD) &
acromioplasty
• CHL release
• SST exposure & debridement
• Triple loaded all-suture
anchor
• Angle > 45°
• Modified Mason-Allen
technique
Treatment
Arthroscopy
2018

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Case Report: SST (R5)
• Subacromial decompression:
bursectomy (SA-SD) &
acromioplasty
• CHL release
• SST exposure & debridement
• Triple loaded all-suture
anchor
• Angle > 45°
• Modified Mason-Allen
technique
Treatment
Arthroscopy
2018

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Case Report: SST (R5)
Modified Mason-Allen
technique:
• 4 limbs passed using
Expressew
• Tie the horizontal mattress
first
• Tie 2 vertical sutures
Intra-articular reassessment
Treatment (cont)

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Case Report: SST (R5)
Modified Mason-Allen
technique:
• 4 limbs passed using
Expressew
• Tie the horizontal mattress
first
• Tie 2 vertical sutures
Intra-articular reassessment
Treatment (cont)

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SR Modified Mason-Allen in Arthroscopy
Suture Passing
Prof. Oh’s operation on Sept 03 2019Castagna A. et al, J.artho, 2007

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SR Modified Mason-Allen in Arthroscopy
Horizontal mattress: rip stop stich
Prof. Oh’s operation on Sept 03 2019Castagna A. et al, J.artho, 2007

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SR Modified Mason-Allen in Arthroscopy
Vertical Simple Sutures
Prof. Oh’s operation on Sept 03 2019Castagna A. et al, J.artho, 2007

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Modified Mason-Allen: Biomechanics
- Among the strongest sutures, comparable to
Double row
(Ultimate tensile strength & Cycles load to failure)
- Least gap formation, no slippage
- Gerber C, JBJS 1994, 1999
- Ma CB, JBJS 2006
- Least tendon strangulation, comparable to
Simple suture
- Less footprint reproduce than Double row - Nelson C, Arthroscopy 2018

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Modified Mason-Allen: Biomechanics
JBJS, 1994

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Modified Mason-Allen: Biomechanics
JBJS, 1994
• Modified Mason-Allen
• Among the strongest sutures
(Ultimate tensile strength &
Cycles load to failure)
• No slippage
• Least gap extension under 200N

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Modified Mason-Allen: Strangulation
JBJS, 1994
JBJS, 1999

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Modified Mason-Allen: Footprint Reproduce
Arthroscopy, 2008

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Modified Mason-Allen: Footprint Reproduce
J Shoulder Elbow
Surg, 2006

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Modified Mason-Allen: Footprint Reproduce
J Shoulder Elbow
Surg, 2006

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Modified Mason-Allen: Functional Outcome
• Constant-Murley score
68.6 ± 5.4 (22.4 m. f/u) JH Oh, 2012
66.1 (30.2 m. f/u) Castagna, 2008
86.11 (26.4 m. f/u) Lichtenberg, 2006
82.2 (16.8 m. f/u) Gerhardt, 2002
88.1 ± 2.4 (30.9 m. f/u) Shin SJ, 2015
• Simple Shoulder Test
9.4 ± 2.6 (22.4 m. f/u) JH Oh, 2012
• UCLA scoring system
30.8 (30.2 m. f/u) Castagna, 2008

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Modified Mason-Allen: Imaging Outcome
• Re-tear (CTA/ Ultrasound)
10.5% (>= 1yr. f/u) JH Oh, 2012
38% (30.2 m. f/u) Castagna, 2008
• Re-tear (MRI)
31.6% (16.8 m. f/u) Gerhardt, 2002
24.5% (26.4 m. f/u) Lichtenberg, 2006
8.5% (6 m. f/u) Shin SJ, 2015

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Modified Mason-Allen: Outcome (JH Oh)
J Shoulder Elbow
Surg, 2012
In the FTRCT group, 202 were evaluated with CTA at
least 1 year after the operation.
Of these, 72 shoulders (35.6%) showed an unhealed
rotator cuff.

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Modified Mason-Allen: Outcome (Shin SJ)
Am J Sports Med, 2015
Statistically significant increase:
• ASES score
• Constant score
Statistically fewer anchors
Retear rate: 8.5%
No difference of functional outcome &
retear rate between MMA & DRSB

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Modified Mason-Allen: Outcome (Castagna A.)
Knee Surg Sports
Traumatol Arthrosc, 2008
29 patients SSP tear >2cm
Clinically significant improvement :
• Constant score: pre-op 37.2 ± 19.5; follow-up 66.1 ± 8.2(p< 0.001)
• UCLA score: pre-op 14.4 ± 5.2; follow-up 30.8 ± 4(p< 0.001)
25/29 (86.2%) patients satisfied.
Retear rate on ultrasound: 11/29 (38%)

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Conclusion
MMA DR
Biomechanics ✅
- Gerber C, JBJS
1994, 1999
- Ma CB, JBJS
2006
Footprint
coverage
✅ - Nelson CO,
Arthroscopy
2008
Clinical
outcome
= =
- Oh JH , JSES
2012
- Shin SJ, AJSM
2015
- Castagna ,
KSSTA, 2008
Imaging
outcome
= =
Cost-effective ✅
Modified Mason-Allen
• Biomechanics: better than other
single row technique
• Outcomes: comparable with double
row
• Cost-effective
• Indication: partial – small full
thickness tear

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Modified Mason-Allen technique
• Biomechanics: better than other single row technique
• Outcomes: comparable with double row
• Cost-effective
• Indication: partial – small full thickness tear
Conclusion

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DR 1x1 Modified Mason-Allen in Arthroscopy
• No1: horizontal
mattress suture
• No2-3: vertical simple
sutures
Tie the horizontal suture
first & preserve its free
limbs for bridging
Tie 2 vertical sutures &
Bridging 4 free limbs to
lateral anchor.
Using double loaded suture anchor

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DR 1x1 Modified Mason-Allen in Arthroscopy
Prof. Oh’s operation on Sept 03 2019

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